My A4000 motherboard repairs.

Joined
Feb 20, 2010
Posts
607
Country
Netherlands
Region
Groningen
I got this motherboard in a defective state. It was already stripped by it's previous owner. So I put all the components back which were removed and to get it working again after I replaced the F245 chip next to the battery.

All SIMM sockets were broken so I removed them and put 3 new ones back with a metal clip. Since SIMM sockets are more expensive than SIMM memory I could now use double sided 8 MB SIMM's.
 

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Awesome! Does that mean that memory capacity is dependant on sockets? The memory depot. is deep waters for me... :)
 
You can use 1, 4 and 8 MB SIMM's on the A4000 motherboard. The 8 MB SIMM's need to be placed in the 2nd and 4th socket.

With all 4 sockets in place you can't physically use the double sided 8 MB SIMM's but now I can. And it's a lot cheaper repairing the motherboard this way.
 
2nd Amiga 4000 board

2nd Amiga 4000 board

Sooooo, here's the repairs on a second A4000 board. Removed the SIMM sockets again and placed new ones.

Also I have replaced all the capacitors but I do that on ALL my Amiga 4000 motherboard. More then ten of them now so a lot of soldering. :)

The board had even more fixes. The F245 chip next to the battery and above the SIMM's was replaced and also the chip above the battery.
 

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Removing SIMM sockets is actually quite easy if you don't want to use them again. The grey/black ones can just break off with a large screwdriver after which I can just desolder the remaining 72 pins.

With the white ones I can just bend out the pins after which they break off. Then I can remove the socket and desolder the remaning pins as you can see in the photo.
 
A4000D being stripped

A4000D being stripped

Here you can see how I remove the grey/black SIMM sockets. Just break off the plastic and then desolder the pins.

Also, this board isn't going to be repaired. I'm stripping it completely to go in a picture frame on the wall. I still have a lot of work to do. :)
 

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