Commodore A3400

[Iggy_Drougge]

We're having troubles with our A3400. It boots fine, but it doesn't recognise fast RAM. There has been some battery leak, but quite modest compared to what others post about here.
The motherboard is rev. B, with the barrel battery mounted north-south, as opposed to some 3400 motherboards where it is aligned west-east. In other word, it is mostly identical with an A4000 motherboard.

[Iggy_Drougge]

Of course removing the battery was the first thing I did. Then I polished the corroded area with a tooth brush and some washing liquid. Now, a week later, it turns out that the F245 chip which sits next to the battery was not only corroded superficially, the acid had even managed to get under the chip and between the board and the pins. I hope changing the F245 will do the trick.

[Iggy_Drougge]

I will try to find my fibreglass pen, but I think the others have cleaned it out further now.

Apparently, it had been stored on its side, so the acid had got into the Zorro slots as well. Some Zorro pins look like old copper, with a green coating. That still needs some cleaning-up.

[Iggy_Drougge]

Update:
A mate in the club measured up the spot beneath the F245 chip. Very bad connections. So he took single copper strands from a cable, soldered one end to the SMD pads, led them through the vias and soldered them on the other side of the board. Thus, the traces were recreated. Then he placed a fresh F245 chip on top of it all, and now the 3400 has fast memory.