Microelectronics | Siemens 80386DX ISA Single Board Computer


Honestly, I bought this board foar spare parts. I originally wanted to extract the CPU and FPU sockets and also the cache controller for my experiments. It was fairly cheap and very corroded under the parallel port. Also some traces of heavy corrosion were underneath the PCB, in the same area. So it was cheap. Very cheap, I could say. The parallel port connector was an old style Harting part with elongated pins. Since I had one of these in my spare parts box (extracted from my defunct Micro Z80 project) I decided to attempt to replace it.


The operation went really straightforward. I struggled a little bit with the rust on the PCB but I cleaned it up in the end. A phosphoric acid based solution did miracles. But then I had to quickly clean with acetone. All this without touching the solder points. I applied these solutions only on the dirty soldermask.

I'm pretty happy with the results.

As a curiosity, this PCB was factory repaired at some point. The job appears to be done by a skilled technician. But it still looks ugly. I've seen better digital PCB repair jobs. Now I'm thinking about using this single board computer somehow.


Here are some pictures that I took during this operation.

For the moment this ISA card will return to the drawer. But it's ready to be used for a nice retrocomputing project.

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