Nintendo Super System (NSS) motherboard repair

I offered to take a look at this because I am a big fan of Nintendo games and hardware and had never had a chance to play with one of these before. It was sold with the cabinet as faulty and missing the sound module, luckily the sound module is very commonly found in Super Famicoms and I just so happened to have a working loose SFC motherboard.

So that was one problem solved, the next one is that the motherboard was completely dead. It has had a rather poor previous repair attempt that did more damage than good as you can see below.

Sound module from SFC fitted.

 

 

Lifted / missing pads and shorted pins.

 

Missing pads replaced with tiny wires and the bent pads straightened and held in place with UV solder mask.

The missing pad (pin 80) is a no connect so I didn't need to replace that but I did use some UV resin on that pin to hold it in place so it cannot short to the pin next to it. 

It's possible the original cpu is working but as I know the one on the SFC board is working and it won't work without the sound module I might as well put the known working one back on the NSS motherboard.

 

With the known working CPU fitted I was still greeted with a black screen but I was expecting this, as even with a dead cpu it should boot as far as the menu using the Z80 cpu.

 

Checking the corner of the board with the BIOS and Z80 cpu under the microscope there was some corrosion next to the super capacitor. The capacitor hadn't leaked though so it must have had a drink spilled on it at some point or maybe another board stored on top of it that had a leaky battery.

 

After cleaning up the corrosion and checking all the damaged traces / vias I found one open trace.

 

 With that patched and protected I was greeted with....

 

 The board is now fully working.