A broken computer and power issues - howto diagnose?

Someone dropped off a broken computer about 15 days ago. The only symptoms were that it didn't boot-BIOS/no-cpu-fan but greem-led-on-mobo was on.

I swapped out the PSU, etc and end result was that the CPU fan was toast (didn't spin on a 3-wire header) and so was a gfx card (tried to POST on the VGA of a working box - PCIe card)

Got it working and sent it back - put in a new fan) - unfortunately today, the box is dead again. This time: the fan's fine, but the mobo cpu-fan won't spin at all (no boot-bios) no matter what i do (swapped the PSU, ram, etc). Green mobo-led is on (same as before).

I tested the cpu-fan (4-wire) on a 3-wire header and the fan spun up but that doesn't exclude the possibility of a the ctrl line on the fan being damaged.

  1. What should I do?
  2. Would it be reasonably honest to tell him to buy a new pc? I'll have to junk the PSU/mobo/cpu/ and possibly ram too.
  3. How do i exclude power issues (bad smps, wall power)? How likely is this to be the cause of his misfortune?

(it's not a cmos issue, new battery, flushed cmos etc)

Reply to
Veek M
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When you have a dead PC start removing things. In fact everything except th e processor. With no RAM, no cards, no drives, ANYTHING connected except th e processor and the power supply it should beep. Usually like three beeps o r whatever in a row, and then it repeats.

If it does not do that, either the power supply, processor or motherboard a re bad.

Reply to
jurb6006

Hey jurb :) away from your usual haunts (freenode) - watcha doing here. Anyway, yep, that's how i did it (removed all the case wiring/drives). The thing is, the first time the mobo conked, the fan was defective.. i put in a new fan and the thing started up nicely.

What I don't understand is:

  1. Is it normal for parts to drop dead like this: 1st the gfx card & fan - which feel like odd components to fail (the gfx card feeds of the PCIe but the fan ought to be way more robust). Then the mobo|cpu conked - the psu is fine, i swapped it out so unless it's (psu) generating transients..

  1. How do I rule out the psu or wall power. I'll probably tell emm to get an i5 for gaming etc so obviously I don't want that to conk on my watch due to bad wall power.

I don't have a data logging multimeter but do those things record transients?

Also would a mobo tester help (me thinks that requires POST)

Reply to
Veek M

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