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I have a Compaq Presario desktop PC model SR1053WM, and it has one of those power supplies that has a little green indicator light right on it, on the machine back. One day that light started flashing and the computer will not turn on. I found a good page about the syndrome at but that didn't help all that much -- suggesting that I get the PC serviced. If I understand that cited page correctly, the flashing green tells me that the power supply itself is OK and that it must be another component causing the fault, like the processor, PCI card or hub, memory or hard drive. I can get a replacement power supply for $57 shipped, supposedly, here http://www.atxcases.com/item.asp?id=1643&desc=compaq-presario-sr1053wm-250&referid=162164. What should I try next to diagnose this? I yanked the power connector at a hard drive and put a multi-tester to some of the pins, randomly, looking for DC voltage. I believe I should see 3.3V or 5V or 12V, if I read the power specs right. All I got was some near-zero readings from my silly digital meter (yeech). Any ideas, please?? Many earnest thanks for considering me :'(

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Dani AI

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Brief recap and practical next steps for 's SR1053WM: the back-panel green LED flashing plus "near-zero" DC readings at a drive connector usually means the PSU is in standby or not being driven on by the motherboard, or that the meter/test method missed the live rails. The LED pattern alone is model-specific; do not assume the PSU is healthy without measuring the rails when the supply is actually switched on.

A safe diagnostic order (no special tools required beyond a multimeter and basic screwdriver):

  • Power down and unplug. Open the case and inspect for bulging capacitors, burnt smell, or loose connectors.
  • Remove nonessential devices (all drives, optical, extra PCI cards). Leave CPU, one RAM stick, and PSU connected to the motherboard only for a minimal POST attempt.
  • Verify meter setup (DC volts, suitable range). On a running PSU check: measure red-to-black = +5V, yellow-to-black = +12V, orange-to-black = +3.3V (3.3V may not appear on Molex; check ATX/SATA pins). If rails are near zero it means the PSU is not being switched on.
  • For bench testing: with the PSU unplugged from the board, PS_ON (green) shorted to any ground (black) will make the PSU run so rails can be measured. This is the common "paperclip" method; use caution (live voltages, charged capacitors). A dedicated PSU tester or known-good spare PSU is safer.
  • If PSU produces correct voltages but the system still will not start, suspect motherboard, CPU, RAM, or a short — try beep-code testing (speaker) and reseat/try alternate RAM. If the PSU refuses to start when PS_ON is pulled low, replacement is justified.

Safety note: mains voltages and stored capacitor charge can be dangerous. If bench tests are uncomfortable, seek professional service or use a PSU tester/known-good unit before buying a replacement.

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