Memory check: passed!

The mailman (actually a woman) had my new memory with her today! It took me all of 5 minutes to get the old 2114L out of the CPU board and the new 40L45 in. Popped Leon’s test EPROM back in and bingo, memory test passed!

The new 40L45 memory.

After that I did the input checks and I’m happy to say that that passed as well. So now all I need are the 3081 driver chips and probably a BC548 transistor (TR3) and the CPU board should be fixed fixed!

These two 3081’s are dead or heavily injured.

This little transistor is looking very suspicious indeed.

So I assembled everything except for the sound board and switched the machine on. There was life… sort of.

It’s alive!

I found the test button to be unresponsive, but when I put the CPU board in program mode using the dipswitch it did kind of start of normally. It was even able to kick the ball out of the out hole and the flippers, some bumpers and the poppers worked. But not much else. So the driver board needs work.

The flippers work.

Also, only two of the five 4×2-digit displays were fully functional, so 3 of them to check and fix.

Only two fully functional displays.

Still a lot of work ahead. To be continued…