Anybody bother to fix newer computer motherboards these days?

[Powermac]

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?

 

[Baron]

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).

 

[Powermac]

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).

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?

 

[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.

 

[Powermac]

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.

 

[Baron]

Powermac Inscribed thus:

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.

Sometimes damage like that, if there is any, can be hard to spot !
There isn't always burn marks or discoloration to give you a clue.

The "Post Boards" are in my opinion a waste of money ! Most of the time
you couldn't repair the fault anyway, thats assuming that you actually
get a genuine fault result ! Those things are really aimed at problem
diagnosis on working boards where, for example, you have a missing
interrupt or bad address.

 

[Powermac]

Powermac Inscribed thus:







Sometimes damage like that, if there is any, can be hard to spot !
There isn't always burn marks or discoloration to give you a clue.

The "Post Boards" are in my opinion a waste of money !  Most of the time
you couldn't repair the fault anyway, thats assuming that you actually
get a genuine fault result !  Those things are really aimed at problem
diagnosis on working boards where, for example, you have a missing
interrupt or bad address.

--
Best Reagrds:
                        Baron.- Hide quoted text -

- Show quoted text -

I ordered the POST card mostly for my older 286 and later motherboards
in my collection. Newer boards pretty much have all the brains in one
surface mounted chip that you cannot replace, but a POST card should
let you know if you have video problems, ram problems, or voltage
problems you can trace back to PS or capacitors that can be replaced.
I hate tossing anything unless it is unrepairable.