P/S internally shorted???Anyone ever see this?

maddog1265

Distinguished
Jan 4, 2006
7
0
18,510
I was checking out a friends Emachines C2684. He said the factory had replaced the mobo under warr about a year or so before. He also said it was "doing the same thing it did before", no boot, fans run and shut off.
The symptoms I reproduced were all fans came on, but no boot I tried the cpu in another board and it worked. I purchased another motherboard and installed it into the emachine case. Upon boot up it went to the bios set up screen. When I hit the F1 key nothing happened. Long story short and two keyboards later. My question is this: Has anyone ever seen a Power Supply internally cross circuit in such a way that it can short out the keyboard circuit in the motherboard? I installed another micro ATX mobo I had in the scrap pile and the same thing happened. The keyboard and the KB socket were shorted out or rendered inop. I have built about three hundred or so units and have never experienced this type of failure. Any comments would be appreciated? Thanks, MD
 
Strange things happen when the PS goes south. Hopefully the mobo is still operable...

I have used sparkle 250W to replace emachines and other matx out-of-warranty if the user does not want a full pc replacement, and I noticed Fortron has a nice 300W 24 pin matx if you want to reuse the case for a mobo upgrade like this this Asus A8N-VM.

They make great media players / PVRs since they are small & quiet!

edit: I looked up the emachine part replacement, for $160 it is not the greatest deal!
 
Sounds like the PSU died and took the mobo with it. Have you tried the KB in another system? Tried removing the mobo and starting the system outside the case? Have another PSU that you can use in the rig for testing?
 

maddog1265

Distinguished
Jan 4, 2006
7
0
18,510
Hello thanks for your reply. Yes I tried the KB in another sysytem...it's toast. I 've checked out other possibilities and it seems as you said the P/S went out and took the motherboard with it...