G.G.I. Corp. IRECSA Phoenix help

[foxyloxy]

I have two GGI Corp. Phoenix game boards with the same fault. There is no sound made when firing the "laser" or when the players ship explodes. All other sound effects e.g. hitting a phoenix / theme music is fine. I have determined the fault is on the top board labelled TIM-8001 (as I have one working game board and have swapped top/bottom boards). Any ideas on which IC might be at fault / where to get a circuit diagram / where to start Thanks in Advance Steve