how to remove cpu from Quadra 840 AV

[habibrobert]

Hello,

Can someone kindly tell me how to take out the CPU out of a Quadra 840 AV? I was able to take off the heat sync, but I don't see any kind of lever or button to press to release the CPU from the board. The service manual didn't mention anything on removing the cpu either. Do I just pry it out with a flat head screw driver? That just seems dangerous lol.

Any advice would be greatly appreciated. Thank you!

 

[MOS8_030]

Here's a thread that shows the empty socket.



The CPU has to carefully come straight up to avoid bending/breaking any pins.

Why to you want to remove the CPU?

 

[beachycove]

I use a 1.5” chisel and slowly lift a little each side, going around three or four times. The pins might bend but not if you do it bit by bit all around. If they do bend, just bend em back. Very easily done.

I don’t think I’d try it with a screwdriver, though.

 

[Unknown_K]

I have a special pry bar that came with a 68040-50 upgrade for my Q950. Very strong flat thin metal slightly curved at the end with teeth that fit in between the pins so it is easy to pop a CPU out without bending a pin.

 

[trag]

I use the long edge of a metal PCI slot cover.

The 68040 is held in the socket by friction.    It often pops loose quite suddenly.    So, you start applying enough force to get it out of the socket, suddenly it's loose, and the edge/corner you were prying on lifts up into the air, leaving the other end in the socket.   Voila, bent pins.

A special tool that lifts all edges straight up, simultaneously would be ideal.  Lacking that, use something that is not a long lever (like the PCI slot cover's long edge).    That way, even if the chip does suddenly come loose, you can't lift the edge any higher than the length of your lever.

Note:  If you're using the long edge of a PCI slot cover, then the length of your "lever" is the narrow width of the slot cover.

Another option is to pry by gently inserting a flat head screwdriver and then gently twisting the screwdriver.  There, the length of your lever is only the width of the screwdriver.

 

[habibrobert]

Hi everyone, 

my apologize for the delayed reply. Thank you all for your input. I was able to successfully get the cpu out by following trag's advice and using a flat head to gently lift the cpu out of its socket.

The main reason I need to take the cpu out is that the board does not work. The board turns on, but produces no visual image on the screen. I know these 840AVs are notorious for going bad, especially if the stock caps have leaked. This particular board has it's stock caps and to be honest, I'm not sure if it's worth it to have it recapped...considering there is no guarantee that recapping will fix the problem. My limited experience with the 840AV is that the traces usually erode once the caps start leaking. 

I don't suppose there are any 840 AV experts out there that would be willing to take a look at this board? I'd to see my 840 AV go dead, but unfortunately it's looking like that. 

thank you again for all your help!