Member Avatar for imnotdavid

a few months back i noticed the light for the power button had stopped working, but the comp turned on. this happened on and off. a short time later, the button stopped starting my computer reliably. but heres the strange part...i could press the button and the comp would start 15 min later. recently i had it randomly turn on after 3 days and then it died some hours later. it went on once more a week later. it could be shut down and booted just fine. a couple weeks later, it is dead again and i feel its permanent. also the light on my LAN card is usually lit as long as an ethernet cable is plugged in. not so when the comp is dead. --so heres what ive already tried: removed everything but power cords from motherboard...even memory. nothing. shorted green and black on 20 pin connector with hard drive plugged in. hard drive spins. shorted pins on motherboard for power button. nothing. shorted pins for power button light. nothing. replaced power supply. nothing...but i noticed the one i bought is 110 volts. the other is 115. sound like the motherboard? is it anything i can fix without replacing the whole thing? if its dead anyway, id be fine trying to solder new relays or something.

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Both and pointed to the two usual suspects: motherboard or power supply. A methodical, low-risk isolation sequence makes it possible to tell which one is failing without a lot of guessing. The notes below focus on diagnostic signs that reliably separate PSU problems from board failures and on safe, practical checks that remain useful years later.

A bench diagnosis is most helpful. With mains connected but the system not running, the standby rail should measure about 5V on the main power connector. The PSU-enable (PS_ON) line should change state when the front-panel switch is operated; a proper transition means the motherboard is attempting to run the PSU. A PSU that provides steady standby but never starts reliably usually leaves the fault on the motherboard side; a PSU that cannot hold stable standby or shows wildly fluctuating voltages points to the supply.

Visual and isolation checks come next. Inspect the motherboard for bulging or leaking capacitors, burned traces, or loose/cracked solder around the main connector and VRM area. Remove the board from the case and test it on an insulated surface to rule out standoff or case shorts. Use a POST speaker or diagnostic POST card to capture BIOS codes — absence of POST with a verified-good PSU narrows the failure to board/CPU/BIOS. Clearing CMOS and reseating the CPU/heatsink can cure intermittent starts caused by bad settings or marginal thermal contact.

Repair vs replacement guidance: boards with damaged VRMs, leaking capacitors, or intermittent behavior under bench testing are usually more economical to replace unless the precise failed component is cheap and the repair skills/equipment are available. Older PSUs sometimes have a mains-voltage selector and must be set correctly; newer units auto-sense. For reliable isolation, prefer a DMM and a known-good PSU or a dedicated PSU tester before committing to a new motherboard or component-level soldering.

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Member Avatar for choybutchoy

why not changing the motherboard, and take note of the hardware that u have and buy a motherboard that it can uses ur hardware at hand, especially the processor...

Member Avatar for Chaky

I'm thinking that this is PSU issue.

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