ATX Power Supply Problems
The Midnight Question Archive
see the new: ATX Power Supply Troubleshooting Flowchart
and Start Your Own PC Business
Copyright 2008 by Morris Rosenthal
ATX Power Supply ProblemsThe Midnight Question Archive see the new: ATX Power Supply Troubleshooting Flowchart and Start Your Own PC Business Copyright 2008 by Morris Rosenthal |
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Troubleshooting your Laptop or PC
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See the new Troubleshooting your laptop or PC (May 2008)3/4/99(Q) Where can I find out how to actually replace the power supply if I find out that it's dead? Composite (A) I've put together a short an illustrated guide to replacing a PC power supply, using a replacement Antec ATX supply in a typical Athlon 1000 system. Morris 3/1/99(Q) I was wondering if you could give me an approximation of how much it costs in electricity to operate a computer. This is a strange question, but my roommate and I are arguing, and I say it costs virtually nothing in kilowatt hours which is part of the convenience of computers, while he says that if my computer is on approx. four hours a day that it costs 20% of our electric bill which is a full bill of $800. I think this is impossible--just so you know, it's a personal computer-300MMX I think, just a plain average computer I bought in 1998. Could you please give me some kind of guess as to the cost of operation, even if you can say it's a few dollars or cents. I'm Canadian too by the way, but I can do the conversion. Michelle (A) Holy %$^&, what do you guys pay per KWH, or is that like a bill for a year? I thought with all the hydro, Canadian electricity was practically free. At any rate, a 14" monitor probably averages around 150W (120Vx1.2A or 220V x .6A) and the system box uses a fairly efficient switching power supply which probably draws less than it's full power rating, normally 200W. So, all in all, a working PC is equivalent to three or four 100 Watt bulbs. Refrigerators are big draws, microwaves draw over a kilowatt when they're running, and of course, nothing comes close to electric heat for a waste of energy. Easiest way to check is to turn the thing on and watch your meter for an hour, turn it off and watch for an hour. If we call it 350Watts for four hours at $.10 per KWH, thats about $.15 (15 cents) a day. Morris 11/20/98(Q) So how about some basic info about the ATX Specification? (This is a repost based on continuing questions.) Anon (A) The ATX specification encompasses motherboards, cases and power supplies. The venerable old AT and baby-AT form factor for motherboards has been changed to move the CPU out of the way of the adapter slots and directly adjacent to the intake of the power supply fan to increase cooling. Also, all of the I/O and any other onboard peripherals now have their ports mounted directly on the back edge of the motherboard, eliminating all the extra cables and associated screw-ups. This requires a case with a double height aperature to allow access to all these ports, not to mention the PS/2 style mouse and keyboard connectors. The ATX power supply replaces the P8 and P9 connectors of the AT design with a single 20 lead connector, which has added a signal line for turning the power supply on and off, and three new 3.3V lines. Morris 11/16/98(Q) The mouse on my Compaq Pentium MMX slowly failed over a period of a few months. I took out the ball, washed it and dried it, but when I put it back, it was just as bad. I tried again recently, but not only didn't the mouse work better, but Windows 95 couldn't find it. Richard (A) Odds are that if you power down, unplug the mouse and plug it in again, Windows 95 will see it. Those small-shell PS/2 connectors are pretty flakey. More to the point, while cleaning the ball doesn't hurt, the more important job is de-lint the rollers. If you look into the mouse body, you'll see two horizontal, spring loaded rollers that press against the ball. Little threads of lint are crested on the rollers from dust picked up by the ball, until the friction contact is lost. You can de-lint these with a fingernail or tweezers, take your time, the results are worth it. Morris 11/5/98(Q) I have an aging Dell Dimension 466V (66 MHz processor) I got for a good price ($0) and spent a few bucks earlier this year installing a sound card, 2M video, and 24X CDR. Also upgraded the RAM from 8 Meg to 40 Meg. Life was good until I bought a digital camera---now I want more speed. Also, the 500 Meg hard drive is getting a bit full (I'm using a parallel port Zip drive to compensate). And since the BIOS is getting a bit old, I'm concerned all will come crashing down on 1/1/00. Should I:
James (A) Milk, Milk, Milk. I'm running this web site (and writing my computer books) on a 486 DX2/66 that I put together in 1994 when I was still full time in the business. Well, it was a AMD DX40 then, but eventually I made the jump to the DX2/66. Along with my CDR, 2 hard drives (for a whopping total of 1GB), and video capture card, I sunk about $4000 into this box. For my last book, I built Socket 7 and Slot 1 ATX systems, covering Pentium II, Celeron, AMD K6 and K6-2, and gave these systems away to family. Why? Because I can practically hear PC hardware depreciating as I type! I'm sticking with my 486 and 14.4 modem as long as my ISP lets me. Morris 10/16/98(Q) I have plans to assemble an ATX system (FIC PA 2013 motherboard, in an Enlight case EN 7233). At a computer club meeting last night, the resident computer hardware "top gun" told me he had unsatisfactory experience with the ATX form. He specifically said that in the event that the system did not shutdown one has to resort to a switch (reset or shutdown?) on the rear of the case. I have been unable to verify this after reviewing various mfg. sites (including Enlight's) as well as a number of guru sites that evaluate boards, etc. My impression, based on the research that I have done, is that the ATX form is superior to the AT for a variety of reasons having to do with the board layout, size, etc. but the "top gun's" statement has me puzzled. Ted (A) Fire your "Top Gun" It's not a matter of choice or opinion. The AT form is dead and burried, all new PCs are ATX. You can buy some conversion motherboards that run in an AT case, but they are a bad compromise. As to his switch comments, who knows what single encounter he's risking his reputation on, but ATX systems have a programmable power switch on the front of the case. A "Power Down" delay can be set, enabling sleep modes to be invoked through the switch, so depending on the settings in CMOS, you may have to hold the switch in for 5 seconds before the system powers down Perhaps this threw him off. I haven't seen an ATX system with a hard switch on the back, but I suppose they might be out there. Morris 10/15/98(A) In Oz (Australia) we use 240 volts - I'm pretty sure that's true for all states, and I believe it's the same for Great Britain, too. Yoy website does not seem to be taking this into account when advising people on equipment. Thought I'd mention it as someone will be bound to follow your instructions to the hilt over here and switch to 115 volts....BANG! Ian (A) I do advise people (somewhere) about the switchability of power supplies, but I suppose I should post this to make a real point of it. I've never lived anywhere outside the center of the universe (USA), except Israel, where they run 230V, which most power supplies support through the little red switch on the back. For some reason, most monitors are not built as switchable, so systems brought from the US to Israel need a transformer for the monitor. Thanks to us scheming Americans, turning on a power supply set at 230V on a 115V distribution system will not always blow it up, it just doesn't draw enough current to function. Morris 10/8/98(Q) I just put together a AMD K6 2 333 and a ASI ATX motherboard. I plug it in and the fan for the CPU spins and the power supply spins but power does not seem to go anywhere else. The HD and the CDrom do not power up. I am at a real loss here. Have you heard of such a thing? Jason (A) That is strange. I've never heard of the fan working when the power supply is in anything but full power mode. The hard drive should spin up regardless, unless it's bad or the lead to it is dead. Try unplugging the power connector to the motherboard just to make sure it isn't feeding the supply some funky instructions, but otherwise, I'd have to suspect the supply itself. Morris 10/6/98(Q) My 286 notebook computer recently died, and I don't see the point of spending money on repairing it. I need a notebook that I can use to prepare manuscripts that I can have printed when I get access to printers. I'm told I need to be able to run Office 95. What sjould I look for and how much will I need to spend. Margret (A) You inspired me to put together a short guide to buying remanufactured and used notebooks, which is reached by clicking on the underlined link above. (Given her price range, she ended up buying a reconditioned IBM Thinkpad, Pentium 133, 1GB hard drive, CD Drive, 16MB RAM, 13" Color, for $800 from a mail-order outfit in NY.) Morris 10/5/98(Q) I have just put together my first computer. The problem that I am having is that the computer won't go to POST. I get no beeps from speaker and no picture or anything on monitor. I have checked and rechecked all cables, jumpers and power supplies. I have used brass standoffs. The only indication that I have power is that the LED power light ( on case, red in color ) blinks on and off. I have a A-Trend Pentium 11 BX motherboard ATX form factor and my case has a 250 watt power supply ATX form factor. The CPU is an original Pentium 11 400 MHz with heat sink and cooling fan attached. The cooling fan is connected to the right power supply on motherboard. I also bought and tried new RAM. Rod (A) It could still be the video card, or an improperly connected power switch, or, what has become an increasingly common problem, an incompatible power supply. This last was never an issue in AT days, but some ATX motherboards will automatically shut off if they don't like the voltage regulation from the power supply, and some motherboard chipsets have known problems with some generations of power supplies. My best advice at this stage is to disconnect everything that you don't absolutely need to get to post. Remove and reseat the CPU and RAM, since partial insertion of either will cause the problem you mention. A bad power switch can also cause this problem, you can try hooking your reset switch to the power on leads as a temporary check. Try an old ISA video card, you should be able to borrow one somewhere. If you motherboard requires that you set a configuration mode jumper the first time you boot, make sure you've done so. If you still can't get anywhere, I'd buy a new power supply for $50, and if that doesn't do it, send the motherboard and CPU back where you got them for exchange. Morris 10/1/98(Q) Hey Morris, I found your site to be most helpful and I'll be starting with building my first computer within the first few weeks, do you think that it is actually cheaper to build a PC from scrach???? Seth (A) Good question- Definitely not. If you are willing to buy mail-order, it's always cheaper to buy a standard built system from a no-name. However, you end up with the cheapest parts that way, perhaps not the ones you would have selected. Also, you may end up having to rebuild it anyway, because the out of box failure rate is pretty high. It only takes an experience assembler 10 or 15 minutes to stick together a standard box with preloaded software, so the dealers can actually make a profit marking the whole up less than the parts. Morris 9/28/98(Q) I determined that my old AT power supply was no longer opperable, so I purchased a new ATX one of the same voltage. My board has connections for both AT and ATX power supplies. When I tried to install it, I didn't know which of the wires to connect to it from the thick black wire connecting to the power switch at the front of the case. The two wires, black and white, coming from this wire left me puzzled where to connect them. I tried to connect them on opposites sides of the green striped wire, on the internal side where you connect the cord. Doing this I got a spark when I turned my computer on. Did I break my power supply in doing this? I'm lost on how to connect this thing. Steven (A) Ouch, you probably fried something. ATX power supplies can't be wired through an AT switch, which is an AC (120V) hard switch. The puzzling bit is what you actually hooked to what here. ATX power supplies are soft (logic) switched from the motherboard. With an old case design, the best bet is to use the Reset switch as the Power switch, and live without Reset. Morris 9/24/98(Q) I bought a new FIC PA-2013 rev 1.1 motherboard, there is also a sticker on the board which says "1.13JF10s". I bought the Enlight 7237 computer case with an Enlight 250W ATX power supply. when I attach the ATX power connector to the board, attached the power switch from the front panel to the RP connector of F-PNL board connector, and pressed the power button, nothing happens (no power from the power supply). I tried this with nothing on the board,, and then I installed the k6-2 300 CPU and 64M of memory and a hard drive, pressed the power button, still nothing happens (no power from the supply). I now that the power supply is working because I tested it on another ATX board. I also shorted pins PWR_ON and PWR_VR on the ATX PS and the PS came on. Sam (A) Hmm, very confusing. Did you check the switch with a continuity meter? The only other thought that comes to mind is the dual use of sleep and power on that cases sometimes impliment differently. Are their two sets of leads from the power switch, and do they act the same way? Morris (R- Sam found the real answer which follows) It looks like the combination of the Enlight 7237 and any motherboard with the MVP3 chipset is a "deadly" one. I found a posting on the problem and called Enlight, they're sending me a new power supply without asking for anything more than the power supply model. The bad one is the that ends with (4901) in the model number. They claim it is because the PS is not ATX 2.1 compatible!!. Sam 9/10/98(Q) Morris, you know alot about computer stuff. Do you have any high-tech stock tips? Dovid (A) Well, you know that there is a wild card here - the stock market is really a modified pyramid scheme. I say modified, beacause stocks (most of them) do have an intrinsic value, it's just that that value is determined by market psychology, and not earnings, history or expectations. Now if you want to know who has some good technology, but a low price because of bad-earnings, bad-press, and lowered expectations, I would recommend AMD (American Micro Devices). Their new K6-2 CPU is a market-place winner, their stock is off about 60% in the last year due to several quarters of losses, and I have no doubt those earnings will turn around. Whether or not the knee-jerk speculators will rush back in when it becomes apparaent that the company is returning to an "up" cycle, I can't predict. Western Digital is another tech stock with a hugely depressed price, like 80%, due to increasing losses. Despite their excellent technology, I'm not sure whether or not their Number #2 position in the hard drive manufacturing game is secure, or whether or not their market share at #2 will hold up. Morris 9/2/98And now, for something completely different. I get a lot of questions from folks starting a PC business. Here's my recollection of that game, and what is said when the workers compensation insurance adjuster comes a-calling.
8/25/98(Q) I am building an ATX computer. I bought an INWIN Full Tower ATX case and an Abit BH6 motherboard. I'm not sure if I have the proper screws/standoffs to connect the board to the tray. What exactly are standoffs, what do they look like, and how do I use them to connect the motherboard? Also, where can I get them if I don't hav them! Nathan (A) The standoffs are the little hexagonal brass bits, that have a screw thread on one end and a screw hole on the other. They come with the case, usually in a little plastic bag. If you don't have any, go to a PC store and ask, they aren't worth a penny. As for lining up the motherboard, see my guide at http://www.daileyint.com/build Morris 8/21/98(Q) I recently purchased a TYAN S1592S ATX motherboard which I installed in a A-ONE case with a SPI power supply. The cpu fan and motherboard light come on as soon as the power cord is plugged into the power supply. When the power switch is depressed, the power DOES NOT GO OFF. The system does not post or boot. The HDD , FDD and CDROM lights do not go on. Working with the vendor, I did the usual of clearing CMOS, disconnecting devices and cards and finally taking the MB out of the case, all to no avail. The vendor sent me a replacement board....which operates exactly the same. I am sure it is a power supply problem...but am not sure if it is in the way the MB is set up or maybe the SPI power supply just does not work well with this particular brand of MB. Roland It's probably the way you have the switch hooked up and CMOS configured. The ATX power supply uses a logic switch, which is controlled by the CMOS settings. On many motherboards, the default setting for power down is "4 second delay". In other words, you have to hold the switch in for 4 long seconds before the power shuts off. It's also possible that the leads from the front of your case to the motherboard are labeled wrong, follow them back to the switch. If you want to double check the power supply, don't plug in any of the switch leads, and see if it still pops full on when you plug it in. The other devices and cards really shouldn't have anything to do with it, unless you have a faulty "WAKE ON LAN" signal coming off the motherboard, which can also be dissabled in CMOS. Morris 8/7/98(Q) I have a 233MHz Pentium II that after moving to a new apartment and plugging in the power cord to the back of the power supply, I immediately heard the sound something burning(also smell of smoke). Now it won't power up. My best guess is it is the power supply. I bought the PC at a computer show in Roanoke, VA in Febuary so the PC should be under warrenty. The actual company is in Ohio so sending it back is not really an option. I went and purchased a new power supply from a local PC shop. It is, however, a 230W instead of the 250W type that came with the PC. Is there a difference? Rolf Did you ever open the case and examine the components for damage? Power supply isn't the first thing I'd suspect. As to your question, a 230W is fine, the 250W may well have been a 230W in disguise. Finally, if you have a phone number for the company in Ohio, call up, get an RMA, and spend $15 to send the system box back (you can hold onto the monitor, keyboard, etc). There's a good chance you have some serious damage, and why should you pay for their leaving a screw rolling around the case, or something never being mounted properly? (Turned out Rolf's guess was better than mine - the new power supply fixed the problem and the old is on it's way to Ohio for exchange.) Morris 7/28/98(Q) I just finished putting together the following system: AMD K6 300 w/MMX, 4 mb agp video card, 3d sound pro sound card, 5.1 gb WD hard drive EIDE, 96 mb edo ram. I installed Win98 with no problems, and everything was working fine for a few days. Then (of course) after a few days, the system decided not to boot.....I would only get beeps from the internal speaker. I looked up the meanings according to the # of beeps, and it seemed like a memory problem (loose chips/bad chips?). I removed and replaced the same chips....and that problem went away. Now, I get erratic mouse errors such as "can't detect mouse" (all connections seem ok), and I've tried 2 different mice on both the ps/2 and serial ports. Also, when the mouse is working, the cursor will start jumping all over the screen....and then locks up. Brian (A) Did you unplug the power supply from the wall, or from the motherboard, before you reseated the memory SIMMS/DIMMS? If not, it's possible that you did a little damage to the motherboard, since ATX power supplies are never really "off". I mention this, because I'm on a crusade. It could also be bad memory where the mouse driver sits getting by the memory check, so you could try rearranging the SIMMs again (unplug the cord from the power supply first). You should also make sure that the RAM is recognized as EDO in CMOS Setup, and maybe try slower timing for it. Morris 7/17/98(Q) Every once in a while I try an experiment with The Midnight Question, this is one of them. I'm currently writing a new book on building ATX PCs, and I'm curious what experience people have had with the "always on" motherboards. A good ATX power supply provides over 700mA at +5V even in it's "off" state, necessary for LAN adapters to provide a "wake on LAN" interrupt, not to mention keeping the motherboard alive enough to cope with the "Wake on LAN", "Wake on Modem" and the software power switch on the front of the case. Now, in olden days, I commonly told people to always leave their power cord plugged in when working on the PC, and to ground themselves on the casing before handling parts or touching anything in the case. Now I find myself telling people the opposite, unplug the power supply before installing more memory or adapters, because the motherboard is never really off otherwise. Does anybody have any good "I blew up my PC-100 SDRAM DIMM installing it in an ATX system I thought was off" stories, or other experiences? Let me know. Morris (A) The following link on the Asus motherboard site has a warning on exactly this subject, along with some graphic pictures of damage: http://www.asus.com.tw/Products/Techref/Misc/atxnotice.html Dick 7/15/98(Q) Do you need a fan with a ATX case and ATX motherboard? Because I know The ATX case is alot more cooling efficient. The processor I will use is a K6 300MHz or a K6-2 300MHz w/ 3dnow.... Scott (A) The ATX power supply has a fan built in, which sucks cool air from the outside and blows it into the case right at the CPU and memory. The CPU still needs it's own heatsink and fan, too much heat generated to disperse via a small surface area. The old AT power supplies sucked warm air out of the case, through the power supply, and blew it out the back, somewhat louder and less efficient. Morris 7/9/98(Q) Your web site came up as a result of me searching for an online database that would return current values for used computer equipment. Is there anything out there like a "Blue Book for Computer Hardware" web site that will allow me to type in Manufacturer, chip speed, hard drive size etc. and have a value returned on its current worth? Alan (A) I haven't seen such a thing, it would be very hard to impliment with anything approaching realisitic values. Blue Books for cars are really a sort of compromise instrument for insurance companies and banks, so they can have some hard numbers to work with. Since car values can be approximated from year to year with a mileage factor figured in, it has some legitamacy. Computer parts prices change by the week, most components prices (with the exception of monitors) have their prices fluxuate (usually downwards) by more than 100% a year. Price asside, the value is highly subjective, since the newer, cheaper components are also better (faster, more capable, more reliable). It wouldn't shock me if somebody is out there assigning phony standard values to things for the sake of tax write-offs, but I wouldn't use it for shopping. By the way, the values for second-hand computers on the page I have posted are all actually higher than I would value the sum of the components, but since they represent a working computer system, they have some value added. Morris 7/1/98(Q) I am looking to buy a new laptop computer as I travel lots and have an old 33MHz one now. What I am hoping to do is buy a fairly low-end computer (maybe a used P-75) and replace the chip (say to a P-166) to improve performance. Can I do this?? I know the P-II are different sizes so I can't upgrade to that, but I am wondering about P-MMX (or P-Pro) chips? Also, assuming that I have enough memory slots in the 'new' laptop, canI move the memory from the old one to the new one? I'm not sure if laptop memory has changed in the number of pins in the last few years. Also (pant, pant...) I was wondering about the heat that a Pentium chip gives off. Is it a big problem buying a desktop CPU for the laptop as they are quite a bit cheaper? David Buying a notebook with the intention of upgrading it is a bad idea. You'll spend far more on parts (everything is proprietary) then you will buying what you want to start with. If your budget is tight, look into buying brand-name stuff that is unsold from last year or the year before, you'll get the warranty, a good battery, and a good price. Also, some of the Internet Auction sites have bargains on older model notebooks, most people don't want them. Don'y buy an off-name, and unless you've worked on notebooks before, don't think about ugrades. I consider myself lucky that I've never broken one on opening them up, the construction includes lots of snap together injection moldings, and unless you have the shop manual, it's a gamble. Actually, even finding all the screws can be a challenge. Morris 6/8/98(Q) I would appreciated it very much if you'd give me your input/opinion about my plan my Gateway P5/60 PC: I can't afford to buy a new machine, therefore, I want to replace the motherboard/CPU and maybe the case (if I have to).I contacted Gateway and was told that any Baby AT mb would do. Do you have any suggestions as to how feasible this is and what mb/cpu would you recommend? Yaroa (A) First, I'd open up the case and double check that the power supply connector is a P8, P9 type, and not a Gateway special. Or, as you point out, you are willing to get a new case/power supply, only about $30, after all, and transfering all of your old components. However, given the ridiculously low price of memory and hard drives, you may find that the only components worth keeping are the floppy, sound card, CD (who cares if it's slow), and modem (hopefully it isn't). Either way, you'll see a tremendous boost in performance if you buy a 233MHz MMX (Intel or other) and a cheap motherboard, combined cost of $200. If you can spare a little more, I'd get a minimum of 32MB RAM ($40), consider a big, fast hard drve ($150 for a few GB). If you decide to replace your modem, talk to your Internet Provider first to see which 56K standard they support. Morris 5/20/98(Q) A friend of mine recently purchased a 440LX (Arist-O AM-607LX) motherboard as part a new PII-233 system he is building. The motherboard has an AT power supply connection aswell as a 'Transfer Connector' (or 'Transfer Wire') for ATX power supply. This 'Transfer Connector' looks like a 2 pin jumper setting and supposedly (as the name suggests) enables support for ATX power supply. How do I go about connecting an ATX power supply to the motherboard?, as there are no connections on the board that match the 20 pin ATX power supply cable. Aaron (A) First of all, thanks for reporting yet another AT style PII motherboard. Now I'll guess an answer. Motherboards don't actually need the +3.3V from the ATX power supply unless they are using 3.3V PCI slots, something you wouldn't need on an AT form board. This leaves just the PS-ON (Power On/Off) signal to account for. I know that people manufacture an ATX to AT power supply adapter with a P8 and P9, and while I've yet to see one up close, my guess is that they spilt off the PS-ON signal with a ground, and that you would plug that onto this "Transfer Connector" to enable automated switching. Morris 5/14/98(Q) So how about some basic info about the ATX Specification? Follow Up to Yesterday (A) The ATX specification encompasses motherboards, cases and power supplies. The venerable old AT and baby-AT form factor for motherboards has been changed to move the CPU out of the way of the adapter slots and directly adjacent to the intake of the power supply fan to increase cooling. Also, all of the I/O and any other onboard peripherals now have their ports mounted directly on the back edge of the motherboard, eliminating all the extra cables and associated screw-ups. This requires a case with a double height aperature to allow access to all these ports, not to mention the PS/2 style mouse and keyboard connectors. The ATX power supply replaces the P8 and P9 connectors of the AT design with a single 20 lead connector, which has added a signal line for turning the power supply on and off, and three new 3.3V lines. For a more complete run down, skip over to my new page on Building the New PCs. Morris 5/13/98(Q) I have a large tower that I would like to upgrade to an BX or maybe an LX Pentium II MB. Trouble is the case is for AT form factor MBs. I know I could replace the case but I would like to keep it and make it the central fixture as a future server or for large storage. It can hold up to 6 full height 5-1/4" size HDs. Do you know anyone who is making the new BX boards, including AGP, USP, PCI for the AT design. And yes, I've looked at at trying to replace the rear panel, but its a spot welded thing - not feasible. Mark (A) I don't think anyone makes a P-II or Celeron, Slot 1 or Slot 2 motherboard that doesn't use the new form factor and require an ATX power supply, which you wouldn't have in an older case. Another less important issue would be the keyboard and mouse ports, mini-dins on ATX motherboards. If anyone is aware of such intermediate motherboards with the BX or LX chip sets, please let me know. Morris 5/12/98(Q) I know someone who bought a computer at a hock shop and brought it home to discover it had a password on the CMOS setup. The computer has a 486 SX Laser motherboard. Is there a manual-override jumper or some way to delete the password? Nathan (A) There is usually a motherboard jumper labled PW or something along those lines, which should be close to the onboard battery. You put the jumper on, wait a few minutes, take it off, and reboot. Sometimes, you have to reboot with the jumper on. Otherwise, you can temporarily remove or short the battery, but you will lose your hard drive parameters along the way. Morris 3/13/98(Q) I've worked for IBM for 30 years, and would like to work on clones. What would be the best track to get trained on clones? I've run across many things that were absolute at IBM, but a hodgepodge in clones. I've noticed in the employment section of the newspaper, many ads are requesting A+ Certification. Do you know of ant books, or schools to train you for certification? Ken (A) I haven't had this question in a while, so I pulled the following out of the backlog. I don't endorse the A+ program, I'm not personally aquainted with it, I've never hired an A+ certified technician, nor am I too keen on certifications in general. However, you asked, and the following answer is provided by Dave. A+ is sponsored (or organized) by the Computing Technology Industry Association.
Morris 2/23/98(Q) I have a Gateway Pentium 200Mhz (non-MMX) computer with an Intel TE430VX motherboard. It is using a 145 Watt power supply, which has become something of an issue since I've been attempting to upgrade my motherboard to Intel's AL440LX (Pentium II) which calls for a 200W power supply. I had just assumed that I would have to upgrade my power supply as well until I found the specs for the TE430VX motherboard at Intel's website. The specs said the same thing as for the AL440LX: minimum recommended power supply of 200W. If this is so, how can my motherboard be utilizing a 145W power supply with no problem, and does this mean that I can get by with this same power supply in the new motherboard? Ryan (A) The motherboard doesn't pull anywhere near 145 Watts, but the power supply has to energize all of the other internal peripherals and adapters. The steady state consumption of the average system is probably under 100 Watts, but there are all sorts of transient demands, such as drives spinning up and seeking, a CD burner turning up the laser or a 10 Watts per channel sound card getting exercised. Also, outside of the best quality supplies, the rating is an exagerated number, I doubt most supplies could really generate a clean 200 Watts for a steady state demand. At any rate, I wouldn't worry about it unless you have several internal hard drives or other "extra" consumption. Morris 1/22/98(Q) I have been shopping for used PC's , and would like to know what I should pay, and what I'll be getting. Composite from many questions (A) I posted a new page today with my view of the value of second hand systems. http://www.daileyint.com/hmdpc/second.htm Please don't look after the fact to see if you got ripped off, it can only make you feel bad. Also, be aware that the sellers are likely to have a very different view of the value of their PC, based on what they have paid for it, but I think the presented information is pretty fair. Morris 12/22/97(Q) Sometimes I get an error message saying that drive D: is missing. Or CDs can't be read. I thought this was my CD ROM till I replaced it. I installed a new 8X speed and it works fine until I shut my computer down. When I reboot it does not see it. If I reboot several times it eventually does. Sometimes on the first try, sometimes on the 7th try. I have checked connections and am stumped. Luts (A) Since you've already replaced the drive, you've pretty much narrowed it down to the controller, or a flakey power supply lead. Try switching the power supply lead first (it's free!). Also, although this isn't your prime issue, don't forget that the most common CD problem is that the discs get dirty. A flannel shirt is generally the best solution for cleaning them. Morris 11/18/97(Q) I just installed a new motherboard and a pentium chip on my friends computer. When I tried to turn the power on the power supply would not work. Can you tell me how to check the power supply to see if it has to be replaced? Blat (A) There are a lot of reasons it might not work, the first thing to do is to simply unplug the power supply leads from the motherboard and see if the power supply fan starts turning when you fire it up. If it does, you probably have the motherboard shorted to the case, or an intenal short on the motherboard. If not, disconnect all the drives, reconnect the motherboard, and see if the power supply works then, indicating a short at one of the drives. Computer power supplies are switching supplies witch require a good load to work, they won't start up with nothing connected. If the power supply fan never starts going, try taking it out of the case, and running it on the desktop with a hard drive attached. If it's still dead, than it's time to get a replacement. To test for a bad motherboard, try taking the motherboard out and running it on the table (with no adapters installed) to see if the power supply works then. Make sure that the black wires on the two connectors end up next to each other on the motherboard connection block. Morris 11/3/97(Q) My friend has a Hyundai Color Laptop Notebook "NEWRON 433SLCC" model 486SLC-33. He has already paid near $100. to be told by the technician that he cannot repair because of the unavailability of circuit diagrams because Hyundai is out of the computer business. My question is the following:
Yvon (A) The best place on the web for tracking down manufacturers on the web is HARDWARE COMPANIES: The Web List . Hyudai has a website at www.hea.com, which includes a contact form and something about repair services. They are still heavily in the computer business, but have apparently discontinued their notebook line. In your friends case, I would think very seriously about abandoning the notebook, since he could probably buy a second-hand 486 notebook for less than the part will cost, if available. Morris 10/16/97(Q) I'm pretty sure this is a power supply problem, but it's more of an annoyance than an actual problem so far. On my Packard Bell 486, when you turn on the (on-off pushbutton) power switch, you hear a soft, high-pitched "zip" and the HD and power lights flash, then go out. I can hear just the faintest hum while the PC is powered on but not doing anything. When you turn it off, after a second or so there's a "pop" from the speakers and the HD and power lights flash again. This is repeated each time you try to power on/power off, until "something" finally catches, the drives spin up, and everything works just fine! A completely unrelated problem that we've worked around... the internal USRobotics 33.6 modem doesn't work (at anything greater than 9600) unless the PC's cover is removed. We just assumed that it's due to heat buildup; the peripheral card sockets are on a vertical daughtercard, so the cards are stacked together horizontally right above the CPU. If you put the cover back on, you'll lose your connection in two minutes or less. Robert (A) The power supply would definitely be my first guess, though it's surprising that a condition like this could continue so long without either getting better or getting worse. The "pop" from the speakers wouldn't worry me, lots of speakers pop whenever they power up or down. One thing I would defintely check is to disconnect all the leads from the power supply, except those to the motherboard, and see if the problem clears up. If not, do the opposite, connecting everything except for the motherboard. You may find that the problem is on a particular lead, and by swapping you may get healthy. Or, you may find that it's not a power supply problem at all. The modem diagnosis sounds good to me. Since this sounds like a slim-line case, and you're having power supply problems, and all the ventallation is done through the power supply, maybe the power supply fan is failing, causing both problems. Who knows, maybe PB has a failsafe that the power supply won't come on if it's fan doesn't spin up. Failing fans, if this is the case, can often be fixed by picking the dust and hair out of them. Morris 9/14/97(Q) I have a 486DX that I can't get to go through a boot sequence. I have changed the motherboard and the cpu. Still nothing no monintor screen or beeps or anything. Do you have any idea as to what I should try next. Kathy (A) I'd check that the CPU is inserted properly, that all the settings for CPU voltage and clock speed are correct, and that you have Bank zero full of good RAM. Try booting the system with only the VGA card installed, and NOTHING else but the power supply and keyboard connected. If you still don't get beeps or a screen, you could have a short under the motherboard, a bad CPU or motherboard, the power supply connected wrong, or a failed VGA card. Morris 8/21/97(Q) Where can I find out about A+ certification? Anon (A) I've had this question from many readers. I don't endorse the A+ program, I'm not personally aquainted with it, I've never hired an A+ certified technician, nor am I too keen on certifications in general. However, you asked, and the following answer is provided by Dave. A+ is sponsored (or organized) by the Computing Technology Industry Association.
Morris 8/12/97(Q) On a recent phone conversation with my brother, he told me that he had just had his computer and printer cleaned, and that he routinely had this done (approximately every 6 - 8 months) as an important part of preventative maintenance. He compared it to having the oil in his car changed regularly. I am skeptical, as no one at the store where I purchased my computer told me to do this. Should I be having this done also to my computer? My brother said it cost about $30.00, which seems a small price to pay if this is indeed a necessary part of regular maintenance. Jo Ann (A) Your brother is being had, and it's a wonder they haven't broken his computer in the process. PC's don't require cleaning, that's something left over from the mainframe mentality, and frankly, it was a cash cow for the manufacturers service arm even then. Printers do require occasional cleaning, dependant on use, but it's always something you can do in two minutes at home, and described in the printer manual. You know when it's necessary because your print starts looking awful. On the other hand, your brother is right to change his oil regularly. I change my oil AND filter every 3000 miles (Dodge suggests 5000 to 7000), and now have 180,000 miles on my 1986 Omni (never a breakdown, gets 40mpg on the highway). By the way, I give my sisters tons of bad advice, and I can only hope they get the real story from somebody else. Morris 8/11/97(Q) I purchased my computer almost 1 year ago, so as you can guess, the warranty is about to run out. Over the past 10 months, it has been in for repair approximately 40 times. They have replaced almost everything in it, and it still continues to make a whistling sound, then the screen quivers, and it shuts down, all before you can even save your work. Sheila (A) A real high pitched whistling is a failing electrolytic capacitor (louder as they heat up), and if you can really hear it, it's a big one. The only place in the computer where you have big electrolytic capactitors is the power supply, and fluctuationg voltage to the bus could also explain the VGA card sending an uneven signal. So, try swapping out the power supply. Morris PS, even if I haven't hit it, the people at your repair shop are jerks. I'd have put your hard drive in a new computer on the second trip and taken this lemon back. 8/7/97(Q) I am trying to find information on A+ certification. I have been searching the web and have not found anything yet. I looking for things like sample(demo) test, white papers, etc. Can you help? Richard (A) I don't really have an answer for this question, but I thought I'd use it as an excuse to make a few obsevations on the training and hiring of PC technicians. I often get mail from people interested in A+ certification, yet I've never hired an A+ certified tech (or met one, for that matter). In hiring technicians, the only thing I was interested in was hands on experience in both hardware and software. Between the two, I put more emphasis on software (Windows 95, Workgroups, DOS and Novell) than on hardware, because 90% of what a modern PC tech needs to know about hardware can be taught in a couple hours. The remaining 10% may take years of experience, but that's what the tech manager is there for. The other thing I look for is general analytical skills, so the best thing you can do for an interview is have a couple good "How I fixed this really weird problem that nobody else could figure out" stories under your belt. A knoweledge of what things cost is also important. Morris 7/15/97(Q) Do you know what voltages are on which colored wires from the power supply to a 486? Paul (A)
Keep in mind that the system power supply is a switching power supply type, and won't operate without a load. The power supply operates by sensing the voltage accross the load and shutting off when it goes out of regulation (high), which generally occurs at a frequency of 20KHz to 40KHz. If no load is present, the supply will either not operate, or the output voltages will oscillate wildly. All output voltages are DC. Morris |