The Interface 1 has had new capacitors and diodes, I haven't yet tested the transistors.
I've replaced the ULA and I've now desoldered the other chips in case they're the cause of the problem.
Now I'm coming to reassemble it I think I might use a cable to connect between the Spectrum edge connector and the Interface 1 because the Interface 1 edge connector support plastic has cracked and it also prevents access to the ROM and the two logic chips.
I'm not too worried about the originality factor, I just want it to work so this is what I might do next.
I'm wondering what people use to read the ROM, my Willem programmer can't read 24-pin chips.
- Interface 1 desoldered connector and chips