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Electronics Repair (sci.electronics.repair) Discussion of repairing electronic equipment. Topics include requests for assistance, where to obtain servicing information and parts, techniques for diagnosis and repair, and annecdotes about success, failures and problems. |
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#1
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Just been handed back a computer that I earlier gave to friends that
were in need of one. It has a problem and I said I'd take a look at it to see if it's something relatively easy to repair. I have never had any reason to give a computers power supply a first look before but at first glance I believe that is the problem. Correct me if I'm wrong. Here's what I have: A computer power light glows amber as soon as the line cord is plugged in. There is no response when pushing or holding the power button. I removed the power supply and started to check voltages. I only found 5.25 volts and 6.5 volts on two pins on the largest power plug that goes to the mother board. The power supply fan never turned on. I know somebody on this group can give me some advice on the info I have given. I'll admit it. I'm lazy and would rather just ask questions rather than dig in or research further. I don't even know if all computer power supplies and plugs are standard. Any help would be appreciated. |
#2
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On Dec 23, 7:54*pm, wrote:
Just been handed back a computer that I earlier gave to friends that were in need of one. It has a problem and I said I'd take a look at it to see if it's something relatively easy to repair. I have never had any reason to give a computers power supply a first look before but at first glance I believe that is the problem. Correct me if I'm wrong. Here's what I have: A computer power light glows amber as soon as the line cord is plugged in. There is no response when pushing or holding the power button. I removed the power supply and started to check voltages. I only found 5.25 volts and 6.5 volts on two pins on the largest power plug that goes to the mother board. The power supply fan never turned on. I know somebody on this group can give me some advice on the info I have given. I'll admit it. I'm lazy and would rather just ask questions rather than dig in or research further. I don't even know if all computer power supplies and plugs are standard. Any help would be appreciated. ATX by far the most common supply, often on sale _cheap_ and connectors are standard. The best 'test' is to simply put in another supply. They do fail occasionally especially if left on 24/7 and yours sounds like a dead one. I think everybody should have a spare especially if they have more than 1 machine. Latest Fry's sale had a CoolerMaster 500 watt for $10 after the rebate so it won't break the bank to have one waiting. |
#3
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Sounds like the 12 volts has died.
I would go for the new option too. |
#4
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![]() wrote in message ... Just been handed back a computer that I earlier gave to friends that were in need of one. It has a problem and I said I'd take a look at it to see if it's something relatively easy to repair. I have never had any reason to give a computers power supply a first look before but at first glance I believe that is the problem. Correct me if I'm wrong. Here's what I have: A computer power light glows amber as soon as the line cord is plugged in. There is no response when pushing or holding the power button. I removed the power supply and started to check voltages. I only found 5.25 volts and 6.5 volts on two pins on the largest power plug that goes to the mother board. The power supply fan never turned on. I know somebody on this group can give me some advice on the info I have given. I'll admit it. I'm lazy and would rather just ask questions rather than dig in or research further. I don't even know if all computer power supplies and plugs are standard. Any help would be appreciated. The most common problem I find is bad electrolytic capacitors. If it's a standard ATX power supply I usually just replace them unless I need it working in a rush. |
#5
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In article ,
wrote: I know somebody on this group can give me some advice on the info I have given. I'll admit it. I'm lazy and would rather just ask questions rather than dig in or research further. I don't even know if all computer power supplies and plugs are standard. Any help would be appreciated. http://www.helpwithpcs.com/courses/p...nc-pinouts.htm In general they're not worth the bother of fixing as they're so cheap. Unless you have the required spare parts lying around. I'm not using a PC for this task and when the power supply failed on this machine it was easier to adapt a PC one and fit it to this PS case than repair it. -- *Time is the best teacher; unfortunately it kills all its students. Dave Plowman London SW To e-mail, change noise into sound. |
#6
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On Mon, 24 Dec 2007 09:30:27 +0000 (GMT), "Dave Plowman (News)"
wrote: In article , wrote: I know somebody on this group can give me some advice on the info I have given. I'll admit it. I'm lazy and would rather just ask questions rather than dig in or research further. I don't even know if all computer power supplies and plugs are standard. Any help would be appreciated. http://www.helpwithpcs.com/courses/p...nc-pinouts.htm In general they're not worth the bother of fixing as they're so cheap. Unless you have the required spare parts lying around. I'm not using a PC for this task and when the power supply failed on this machine it was easier to adapt a PC one and fit it to this PS case than repair it. Thanks to all. Yes the supply is dead. No 12 volts and the two sockets readings at 5.25 and 6.5 volt are not correct. The above link was helpful. I do have a question though from the link. It says at the bottom of the page: "To power up an ATX or ATX-2 PSU for testing, short pin 14 (PS_ON) with one of the grounds" I did this and it made no difference. Does this mean on a good supply on the bench that these pins have to connect to get all the various voltage readings on the various pin outs? |
#8
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wrote:
Just been handed back a computer that I earlier gave to friends that were in need of one. It has a problem and I said I'd take a look at it to see if it's something relatively easy to repair. I have never had any reason to give a computers power supply a first look before but at first glance I believe that is the problem. Correct me if I'm wrong. Here's what I have: A computer power light glows amber as soon as the line cord is plugged in. There is no response when pushing or holding the power button. I removed the power supply and started to check voltages. I only found 5.25 volts and 6.5 volts on two pins on the largest power plug that goes to the mother board. The power supply fan never turned on. I know somebody on this group can give me some advice on the info I have given. I'll admit it. I'm lazy and would rather just ask questions rather than dig in or research further. I don't even know if all computer power supplies and plugs are standard. Any help would be appreciated. If you plan on doing any computer h/w work, a p/s tester can be picked up for $20 and it really makes life easier. http://www.pcpower.com/accessories/a...ly-tester.html |
#9
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Just like many other thingys,,, there is a big difference in Quality
computer power supplys.You buy cheap, you get cheap. cuhulin |
#10
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On Dec 24, 11:04 am, wrote:
It says at the bottom of the page: "To power up an ATX or ATX-2 PSU for testing, short pin 14 (PS_ON) with one of the grounds" I did this and it made no difference. Does this mean on a good supply on the bench that these pins have to connect to get all the various voltage readings on the various pin outs? Unfortunately that test can only result in a probable result - a 'maybe'. Test that would have reported 'definitively good' or 'definitively bad' means disconnecting nothing, less labor, faster testing, and numbers that mean the better informed will reply. Less than two minutes using a 3.5 digit multimeter. A tool so 'complex' and 'scary' as to be sold to K-mart, Radio Shack, Lowes, Tru-Value Hardware, and Walmart customers. Some good power supplies will not power when disconnected from computer with pin 14 grounded. Some defective power supplies will power when pin 14 is grounded. Some power supply problems may actually be created by the power supply controller which is also not found using a 'pin 14 grounded' test. Best way to identify a defect faster and to obtain numbers so that others will provide useful replies is summarized in "When your computer dies without warning....." starting 6 Feb 2007 in the newsgroup alt.windows-xp at: http://tinyurl.com/yvf9vh Power supply testers are also inconclusive as the 'pin 14 grounded' test. Money for a power supply tester that will not provide a definitive answer, that has no other purpose, and that still cannot report a replacement supply as good? Same money is better spent on a multimeter. A computer can still boot even if the new supply is defective. Is a new supply good? Only useful answer means numbers from that multimeter when a best load - your computer - is connected to that new supply. Grounding pin 14 can result in 'maybe the supply is defective'. Power supply tester can only imply a good supply. 'Maybe' means the supply and the rest of that 'power system' is still unknown. A 'system' has three possible states: definitively good, definitively bad, and unknown. Only way to establish 'definitively something' means numbers from a meter during maximum load. |
#11
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my 3year old dell started having problems and it was the
power supply . it would turn on fine and the lite on front came on,but it didnt compute right. lucas http://www.minibite.com/america/malone.htm |
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