Test PSU

Discussion in 'Windows 7 Hardware' started by seekermeister, Aug 16, 2013.

  1. seekermeister

    seekermeister Honorable Member

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    I ran a test on the PSU on my Lenovo Think Centre M52 8215 which won't power up any longer. It seems that while the ATX plug tests good, none of the others do. I would just assume that means that the PSU is bad, but what throws me is that I would have thought that at least the case fans would spin with just the power through the ATX cable.

    I've checked to power switch circuits by crossing the pins on the motherboard, and it still doesn't power on, so obviously that isn't the problem. The only question is the one mentioned in the first paragraph...should the case fans spins with just the ATX power, if there wasn't some kind of problem outside of the PSU?
     
  2. seekermeister

    seekermeister Honorable Member

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    When I remembered that I had a spare PSU in the closet, I dug it out and connected it to the PC, and it still won't power on. I guess that means that the problem is in the motherboard itself, since I think I've ruled everything else out. At this point, I'm beginning to think that fixing this isn't worth the time and expense, but I still didn't lose anything moneywise, because of the components that I can salvage from it. Still,it would been nice to get it running.
     
  3. BIGBEARJEDI

    BIGBEARJEDI Honorable Member
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    Did you use a Multimeter to make the determination that the ATX plug was good, and the other power connectors were bad? :confused:

    If so, what were your voltage readings? (for example: +5.00vdc, +12.00vdc, -5.00vdc, -12.00vdc, etc.). When PSUs fail, and internal components fail, it can overvoltage the components getting power from the Motherboard--for example, case fans and lights. They can do unpredictable things with both overvoltage and undervoltage to them.

    I had one couple of months back that was not reading correct voltages, so I ordered a replacement (HP), and plugged it in and it appeared to have correct voltages on Multimeter. Until I connected Mini-ATX connector to Motherboard, and lights blinked on and off instead of staying on steady (power LED), and the case fans spun up, spun down, and then turned off! o_O That's a sure sign the Motherboard circuitry has shorted out. The place I got the PSU from is an authorized HP parts reseller and they test 100% of their PSUs on load and no load.

    Sounds like the Motherboard is at fault, since you threw a 2nd known good PSU on it and it failed to operate. Sometimes, you'll get lights, no lights, fans, no fans, or a combination of all as per my story above. :wink:

    ThinkCentres are IBM and made really well. You might consider Motherboard circuit repair; they run around $100; I personally don't use those services but I know Techs who have with limited success. If you can't afford to lose the $100 I wouldn't do it, it would either junk it and use for spare parts, or try and find a Refurbished Mobo on eBay and re-purpose it.

    BIGBEARJEDI
     
  4. seekermeister

    seekermeister Honorable Member

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    I already opted for your last suggestion and ordered a replacement on eBay. It has already arrived, but I haven't tested it yet, because it didn't come with the hold-down bracket for the processor's heat sink. I have to buy a set of allen wrenches to remove the one from the old motherboard, since I can't seem to locate the ones that I have.
     

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