Atari Asteroids Deluxe repair log

Sometimes lightning does strike twice.

I was recently sent an Asteroids Deluxe PCB which was exhibiting corrupted vectors.

When I got the PCB, I put it on my test rig and was presented with the following in TEST mode;

GAME mode;

The symptoms were pretty much identical to the last Asteroids repair log I posted.  Note however this is an Asteroids Deluxe, however it is pretty much identical hardware to Asteroids except that Asteroids Deluxe has a pure digital sound circuit via a Pokey chip (Asteroids is analogue and no Pokey).

I immediately probed the 74LS42 decoder at E6, which had two outputs stuck HI.

So I desoldered it;

Tested it in my IC tester;

Socketed and replaced it with a fresh decoder;

Fire her up again;

Now working, except that the PCB would sometimes crash or refuse to boot.  I was able to determine that three of the six ROM sockets were worn.  So I replaced all of them for reliability;

Now working 100%.