Fried PSU, what to replace?

April 29, 2009 at 18:59:38
Specs: Linux i686, AMD X2 1500mhz 3GB RAM
So I made the stupid mistake that no man should make and bought a cheap PSU off ebay for an old PC I was putting together to make an HTPC. After very little use I got a smell of burning and nothing would come on the screen. Fans whirred as and all the lights came on.

I replaced the PSU with the one from my everday PC but as expected things were the same, so something has clearly gone wrong permanently in my HTPC. I tried replacing the graphics card to no effect and tried removing the RAM or the graphics card to see if the PC would make its usual beeping sound to tell you something was missing, it didn't.

So clearly the problem lies with the CPU and/or Motherboard (and maybe the RAM but we haven't got there yet!). I tried removing the CPU and turning on, this caused the PC to react exactly the same, suggesting a CPU problem.

Now what I would like to know is when PSUs normally go what components normally go with it? From what I've told you does it seem that it might be just the CPU which has gone? If both have gone its an annoyingly expensive replacement for old components!


See More: Fried PSU, what to replace?

Report •


#1
April 29, 2009 at 19:44:40
When a PSU blows, it's a crap shoot as to which other component(s) gets taken out along with it. If you're not getting any beeps when you try to boot the system, it's probably the CPU but it could also be the board, possibly even both. Don't just randomly replace parts.

Report •

#2
April 29, 2009 at 20:11:42
A CPU generally doesn't fail nearly as often as the motherboard does, with the exception of maybe the old Slot 1 processors. In my experience, PS failures typically take out the motherboard and don't usually touch the RAM or CPU. In some cases the RAM and/or the CPU can be damaged, but in most cases not.

FYI, even trying to boot a fully functional motherboard without a CPU usually doesn't cause the motherboard to emit a beep code. I read somewhere that the CPU does a self check on each component at bootup by executing instructions from the BIOS and it's the one that has to initialize the beep to begin with. If the CPU's gone, the self check can't be done and thus the motherboard cannot beep if something's missing. If there's a motherboard failure or a problem with an expansion card, that can cause the motherboard not to beep as well.

WinSimple Software
CompTIA A+ Certified


Report •

#3
April 29, 2009 at 20:29:27
[quote]FYI, even trying to boot a fully functional motherboard without a CPU usually doesn't cause the motherboard to emit a beep code. I read somewhere that the CPU does a self check on each component at bootup by executing instructions from the BIOS and it's the one that has to initialize the beep to begin with. If the CPU's gone, the self check can't be done and thus the motherboard cannot beep if something's missing. If there's a motherboard failure or a problem with an expansion card, that can cause the motherboard not to beep as well.[/quote]

Well thats exactly my point, if its acting as though its got no CPU in when it does, then that makes it look like the CPU is faulty, or does this not follow?


Report •

Related Solutions

#4
April 29, 2009 at 20:32:15
What Rayburn wrote is correct...I probably should have expanded more. The CPU must be functional for a beep code to be emitted. The board must be functional as well. If both the board & CPU are good, beeps *should* be emitted if either the RAM or video are bad.

Take out all the RAM & try booting the system...if you don't get a repeating beep code, either the CPU or board are defective, possibly both.


Report •


Ask Question