I got an Amiga CD32 without colour on the S-Video output on my work bench.
Schematic of S-Video ouput.
I tested input signal (Base) of the Q282 2N3904 (NPN) transistor, result is ok (see picture above).
That’s not what it should be, so replaced transistor Q282, result after replacement is still the same. I removed C282 to isolate Signal between Q282 and output connector (CN9). Signal is still like the picture above, so transistor Q282 and C282 are not the problem.
Let’s see if I remove R284. Signal still the same, but… Resistance of R284 is 0 – 0,1Ohm, hmm that should be 100Ohm, let’s replace it and test again.
Signal on pin 1 of C282 is like above, so that’s good. I placed a new C282 and signal is still good, also after C282 without bias voltage.