Help with a diagnosis please

[frasermcdonald]

HI,
My sons pc blew 24 hours ago .
The psu let out a large flash and bang and smelt smoky!
I bought a new psu but computer will not start - so I put it into another pc to check it was ok and it was. Removed drives graphics and memory and wouldn't start then it did ... briefly... three beeps which means on the bios 64k base memory fault. Thought likely I had blown MOBO as spare ram we had did not help.
Bought new mobo today nothing will start .
checked with voltmeter that on off switch working it is.
Put another PSU in just to check - no joy.
Will not start in any config it ( new mobo ) has onboard graphics that wiil be replaced but even with/without ram and drives will not start or give a bios report.
I'm down to thinking gubbed new MOBO on delivery or gubbed CPU which is a athlon 64x2 6000+
I've checked its cpu fan and it works elsewher
Any point in trying power up with no cpu I thought boards wouldn't do that without cpu/fan?

Any advice trying after this to avoid £40/50 computer shop charge!!
Fraser
Any advice welcome

 

[Mycologist]

You say that you tried with a new mobo, and then later that you think the cpu and/or mobo may be dead, but you don't say if it is a new cpu or not, so if it's the old cpu, it's likely that's dead.
However the more important thing that comes to mind is whether or not you have tested each of the components separately in a different pc, seeing that if the psu in a manner as spectacular as you describe, it would suggest that any of the components could have been totally wrecked, if there was a sufficient voltage spike for example.
In addition, you may want to open up the dead psu, and see what exploded, most likely it was caused by plagued capacitors, but once you've isolated what it was, it might give a clearer idea as to what it may have done to the components. But yeah failing that just test out each component in a different pc individually to test which ones are fried.

 

[frasermcdonald]

Thanks for the help, but my sons failed to inform me that they had destroyed the front two usb slots on the case, and when looking into another thread, Dcrewchief said "try unplugging your front usb ports from the header pins on motherboard and see it powers up. just a thought maybe it will work"
I took the usb header pins out and now the computer has started up with the new psu and mobo, though I have not yet tested everything. However I could not test each component individually as my sons computer is the only dual core and ddr2 ram pc in the house. All other computers are too old to test new parts on.