A1 CPU module reparation

I'm trying to organize something, first from France or nearest countries, but who knows. So I'm looking for guys with defective CPU module and whishing to try a reflow, a reballing i.e. those for which CPU is *NOT* dead.

@abalaban

Replace the battery first, and then try a different PSU.

If that does not help connect a null modem cable to Serial (RS232) port, if you don't get any text from serial port then your CPU is most likely dead.
(use putty or hyper-terminal to display the text.)

If you do get text, then I suggest you look for problems whit RAM or Graphic card or PSU.

Hi @LiveForIt
Um, you kind of missed the definition: " to reball".
Look here:
http://www.youtube.com/watch?v=jQeanpujmuM
Nice 'Electropoint' video...

@Snuffy

Are you sure that's the problem? I've seen many A1s with "intermittent CPUs" where pushing on the CPU made it work.

In all cases, the problem was not the CPU or the soldering to the module, but the fact that the module wasn't sitting straight and the socket was not making good contact.

Have a good look from the edge of the mobo and check that the CPU module is parallel to the mobo. As supplied, the nylon spacers were the wrong length (too short IIRC). When I made up new spacers for the CPU modules, they all worked OK and are still working AFAIK.

@tonyw

Ive goto get around to getting my A1 tested :) bloody busy with the wife and 6 kids spare time is very limited to none :( hope i can get around to it soonish

@poweramiga

No worries mate, I'll be there at the meeting next week if you can make it.

Hi @tonyw

Are you sure that's the problem?

No, I'm not. To me it's just another connection to consider. If the A1 worked for awhile and then stopped and refused to budge and a logic probe showed CPU signals of life, then what? It could have been a case of uneven CPU heat over time disturbed/warped the surface. I agree with you; look over the terrain and really try to get a picture of CPU & module surfaces. How about a bad application of heat sink grease could have started it. If I were to do something, I would remove the CPU module and heat sink and spray clean the area and components. When I redone mine in the first year I had it, the cooling system was reworked. I would say if my cleanups didn't get anything going , then the repair center should hook up the oscilloscope and take a better look to see if the CPU is really dead.
Another component that will leave you in the dark literally, is the U-Boot Rom chip. It does all BIOS switching to the OS. So if the CPU is fine, nothing will happen until U-Boot says so. The low profile chip socket can cause a bad connections. I've removed mine and spray cleaned the chip and socket and got a totally 'blackout' video going again. That's it; connections.