Motherboard/cpu fault

[jos1]

I have a fault but how do I decide if it is the motherboard or the cpu without replacing one of them?

[Bigeye74]

whats the fault? and whats it on?

[jos1]

Hello BigEye74. The motherboard is ASUS A7V-8X-A-L fitted with Athlon XP200. On switch-on there is an almost immediate failure of power. The power supply is OK with no short circuits on any output and all other were disconnected in turn to isolate them without success. What next?

[Bigeye74]

IMHO the fact that you are cutting out so early says motherboard to me especially if you aren't even getting to the bios screen. Without paying for an expert (waste of money) it would be difficult to tell. How to you know the PSU is good?

[jos1]

Thank you again. I thought that it was the motherboard but another opinion would be useful. I know that the psu is OK as I checked its outputs against suitable loads. It is my spare computer so whether I get another motherboard or use it for spares remains to be decided. All the other hardware is fine and the case is excellent.. Thanks.

[ACtheTROLL]

what state is your heatsink in?

athlons are known for high running temperatures ... and can reach critical temperature in a couple of seconds. The thermal cutout does it's job .... and by the time you've reached for the button ... you are back down to running temp ready to cycle again.

normally when it's the mobo (pcbtracks) the inside of the case needs to warm up ... which generally takes longer.

and if the power capacitors blow ... it won't power up.

no guarantees ... but they don't all look like dandelion clocks. Shine a torch through the fan look for dust bunnies.

careful you don't nudge the heatsink and break the thermal paste.

[Bigeye74]

Trolls post reminds me of a fault where dust had built up around the capacitors around a USB outlet. I got the vacuum cleaner on it (a BIG no no!!!) and problem solved.

[ACtheTROLL]

also check that the fan works!!