To replace MOBO in Emachine T2642

[JimJames]

I'm attempting to repair a friend's Emachine. Initially I suspected
the power supply and replaced it with one I purchased at a local PC
store. The machine's still dead. Using the component by component
technique I guess the motherboard would be the next usual suspect.
Finding the right one and practicing the right procedure after install
will entail me wading out of my depth.

So, in short, my questions are:

- What is a good, inexpensive replacement for the MOBO that's
supplied in a T2642 (the processor is Intel/Celeron)?

- Will I need to reinstall the Emachine software or will the system
boot up using the OS on the existing hard drive?

- What are the other, well known weak system components that come
from the Emachine factory?


JimJames

 

[Dave]

I'm attempting to repair a friend's Emachine. Initially I suspected
the power supply and replaced it with one I purchased at a local PC
store. The machine's still dead. Using the component by component
technique I guess the motherboard would be the next usual suspect.
Finding the right one and practicing the right procedure after install
will entail me wading out of my depth.

So, in short, my questions are:

- What is a good, inexpensive replacement for the MOBO that's
supplied in a T2642 (the processor is Intel/Celeron)?

- Will I need to reinstall the Emachine software or will the system
boot up using the OS on the existing hard drive?

- What are the other, well known weak system components that come
from the Emachine factory?


JimJames

Bail out, now.

What, you didn't listen?

OK, don't say I didn't warn you. First, define "dead". Does anything at
all happen when you hit the power switch? Have you tried shorting
(momentarily) the pins on the motherboard to see if the power switch is
working? (a power switch on an ATX mainboard is momentary contact)

If you are determined to replace the mainboard, and assuming this is socket
478 with onboard video (and possibly an AGP expansion slot), you need the
following:

http://www.mwave.com/mwave/viewspec.hmx?scriteria=BA21930&RSKU=BA21930
(that should probably work)

However, If you try to install any emachine software on that, I will hunt
you down and kill you (just kidding)
Seriously, that's not a good idea.

You will need a non-proprietary version of Windows to get the machine
running again. A "restore" disk won't do it. Now some idiot is going to
pipe up and say that the easy way is to remove all the hardware drivers from
windows control panel, blah blah blah. That ignores a couple of things.
First, the system is "dead". Second, just like most shortcuts, it's very
risky. At best, you might get a really slow running system with lots of
random errors that are going to drive you nuts when your buddy is calling
you every 30 seconds. At worst, you'll lose all your hard drive data and
have to start over reinstalling Windows anyway. There is a right way to do
this project, and the right way is going to be time-consuming. Very.
Remember I told you to bail out, now?

Brand new celeron systems can be had for about $300. I'd suggest a whole
new system. The weak component of the emachine? Pick one, you can't
POSSIBLY guess wrong. -Dave

 

[JimJames]

Bail out, now.

What, you didn't listen?

OK, don't say I didn't warn you. First, define "dead". Does anything at
all happen when you hit the power switch? Have you tried shorting
(momentarily) the pins on the motherboard to see if the power switch is
working? (a power switch on an ATX mainboard is momentary contact)

~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

Thanks Dave. You offer lots of great advice, especially that first
bit. :-D

By dead I do mean that nothing at all happens when the power switch is
pushed, except for a clicking noise from the switch itself. Shorting
the pins? I didn't do that. Of the seven pins available -- six of
them occupied by three, two-holed plugs -- which of them should I use
to complete the circuit???

JimJames

 

[Dave]

Thanks Dave. You offer lots of great advice, especially that first
bit. :-D

By dead I do mean that nothing at all happens when the power switch is
pushed, except for a clicking noise from the switch itself. Shorting
the pins? I didn't do that. Of the seven pins available -- six of
them occupied by three, two-holed plugs -- which of them should I use
to complete the circuit???

JimJames

That's easy. Look at where the power switch from the case plugs into the
mainboard. There should be a little two-conducter plug sitting on two teeny
tiny pins. Pull that plug up (should move easily with your fingers). Just
remember which pins the plug is on, in case the mainboard is not labelled
(but most are labelled, something like "power_sw"...the plug is reversible
so you can't hook it up "backward", but you have to have the plug on those
two specific pins, regardless of which direction the plug is facing).

Now, the two little pins on the mainboard that the power switch plugs into
are the two pins you should (carefully, and momentarily) short, with
something like a small screwdriver. You are mimicking a momentary contact
switch, so if you short the pins for about half a second or less, that
should do it.

If you still have nothing at all happen, triple check ALL your connections
between mainboard and case and power supply. Also make sure that the main
power switch (on the power supply) is on, and that the voltage is set
correctly on the PSU.

Still no joy? Yes, you likely are looking at a bad mainboard. Or, two bad
power supplies (it's not out of the question) -Dave

 

[Tweek]

I replace these motherboards all of the time. The dead boards are all
accompanied by a dead or dying power supply. You need to find a board with
the same or similar chipset, in this case the Intel 845 series. I have found
them at www.hypermicro.com
When you boot the machine with the new board installed, it will boot to
windows normally but you will get a message about activation. You will
probably have to call to do it, but make sure you select 'change product
key' and enter the key on the back of the machine before you read off the
activation ID to the computer. Once that is done you can install any drivers
specific to the new motherboard. The Emachines keys are the only OEM keys
that I have found that MS lets you activate.