As everyone is probably aware now I have been having a heap of trouble with system 9 sound.Finally got sound on a machine, without the speech board (jumpered W1 W2).
Then plugged the speech board back in, sound no speech, gaps in sound where speech should be.
Other symptom, whenever the speech board is plugged in, sound is at a very low volume.
Also a fair bit of static, like a crook pot.
Did the usual, elect caps, checked other caps and resistors. Tested eproms so I knew they were OK. Ribbon connecting cable tested fine. So did the pot.
Read a heap on the net. Found a few bits and pieces pointing me in the right direction, but essentially there is no real info out there for the speech board.
Finally decided to replace IC2. Even though symptoms pointed to it being OK.
New socket and the IC's are readily available at Jaycar.
Now finally had speech,
but volume was still extremely low.
Thought about it for a while and figured if IC3 also an op-amp then perhaps it is faulty too.
Changed it and Bingo full volume.
Hopefully this will help someone out sometime,why both items chose to go at once is anyones guess,but apparently it is not normal, and gives different symptoms to either one of them failing independently.
