Hi guys
Recently acquired one of my all time favourite games from back in the day - I put so much lunch money into this every day for about 6 months ! Don't tell my mum though
When I first got it I immediately realised some sounds were not correct.
#1 The player shot/firing was an extremely high pitch and annoying 'pew pew'.
#2 There was no explosion sound when the enemy ships or your ship exploded
I'm new to all this so after much googling I found someone with missing sounds suggesting replacing the LM3900N Op Amp at IC37 can fix some sounds. This is on the main board hidden below the small speech board.
I removed, socketed and replaced it . No difference.
After more googling I then did the same with the LM324N at IC46.
Success ! I have the correct ship firing noise and all the explosion noises back
See pic below for the 2 ICs I replaced.
So, very happy to have the correct sounds
HOWEVER with a working LM324N in place
I now have the *loud* static hiss present - which I believe is a very common issue.
This wasn't present when I had the missing sounds and the faulty LM324N in situ. So I'm assuming it must be something to do with this part of the circuitry ?
After reading around I'm failing to find a definitive fix for this issue. I see some suggestions regarding adding caps or more grounding. I also see folk saying you won't fix it and just live with it ? This seems pretty odd - surely they didn't come out of the factory like this ?
Any new thoughts on this ? I appreciate there are a few older threads already on this but resurrecting them doesn't always gain traction.
Thanks in advance.
