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)

A broken computer and power issues - howto diagnose?
 

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

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

A broken computer and power issues - howto diagnose?