Trol
Professional
This pcb was missing the 054986A module and had the sound ram @2D and the sound rom @7C socketed.
The Z80 and the ram @ 6C had been replaced and the 054539 was reflowed.
So I was expecting sound circuit problems
Ordered a 054986A repro from Caius and after fitting it, the game reported sound ram @ 2D bad.
The ram itself tested good in my programmer, so after a bit of swearing, beer and a little help from Caius, I started to look for broken traces and so on.
Found a tiny bridge on two pins of the 054539 custom, removed it and teh game is working 100%.
The Z80 and the ram @ 6C had been replaced and the 054539 was reflowed.
So I was expecting sound circuit problems
Ordered a 054986A repro from Caius and after fitting it, the game reported sound ram @ 2D bad.
The ram itself tested good in my programmer, so after a bit of swearing, beer and a little help from Caius, I started to look for broken traces and so on.
Found a tiny bridge on two pins of the 054539 custom, removed it and teh game is working 100%.