On Mar 24, 6:09*pm, Baron wrote:
Powermac wrote:
On Mar 24, 4:40*pm, Baron wrote:
Powermac wrote:
Anybody here bother fixing computer motherboards these days? I have
seen a few that just need capacitors replaced, but what about the
ones where the power supply took out the board, are they fixable?

I have an emachines motherboard (K8MC51G) that powers up when I
push the power button, but doesn't post of even beep an error code.
Seems to be a common problem, the PS it came with still works
(tested in another system), and there are no burn marks or
capacitors bulging/ leaking that I can see. Was wondering what
could be the problem (used different CPU's, RAM, and a new 550W
PS). Is there a common fix for that model?

Are those PCI/ISA post boards on ebay useful for figuring out MB
issues?

Yes its a common repair ! *Replacing bad caps often extends the life
of a machine. *Emachines... Yuk *Look for pin holes in the bridge
chip(s).

--
Best Regards:
Baron.

Pin holes in the plastic chip housing? So you are saying a chip blew
up and in doing so poked a hole in the casing?

Yes ! *Quite common. *Sometimes you have to remove a heatsink to find
one. *I've seen the RAM PSU switcher chip simply vanish ! *Just the
bits of lead frame attached to the board.

Another interesting failure mode, is the CPU PSU switching chips getting
so hot that the solder holding them melts and they slide off the pad
and generally destroy things.

--
Best Regards:
* * * * * * * * * * *Baron.- Hide quoted text -

- Show quoted text -

Nothing on the board seems missing. I took the heatsinks off the
Geforce chip (odd there was no heat distribution grease or pad, it
must run cool) and it looks fine. I took the heatsinks off the chipset
chip (it had a heatsink heat transfer pad) and the chip looks like it
might have launched a piece off from the side (heatsink pad is missing
mateial in that direction that is in a lump on the edge of the
heatsink). So looks like the main chipset is blown (doesn't looked
cracked or overheated, but it would explain no error beeps on
startup). This board is junk, but I will test it with a PC post card
when I get it just for the heck of it.