I wanted to take a spare PCB, you know- just in case! I had some spares that were in the ‘working’ pile but best test them! And… both not working! Typical! One seems dead but the other was giving the now familiar beep codes!
First 5 high 1 low – replace 2114 ram at p3, plug it back in – 4 high 1 low bad ram at n3 – working! One of the ram chips in this area had already been replaced so maybe this particular brand of 2114 is prone to failure.
Very glad for the beep codes as I don’t have a test rig where I can test Asteroids pcbs on the bench, I’ll have to look into that as a future project
