One of my Apple Language Cards causes the following to occur:
The screen filles with the symbol '?' and the system locks up.
I have never seen this before, and I'm unsure what would cause it. Have any of you see that happen?
I suppose it could be a faulty 4116, but IIRC, I pulled the RAM and it still happened, and the Apple language card should work with the RAM removed.
The cost of replacing them all would likely be worth the time savings IMO.
Does this card have the F8 ROM in it? Try pulling that one first, then testing.
That is something that I may have done, but I can but check it again with the AutoStart ROM removed.
As for components, I have a selection of spares, and I try to hold onto any old boards with useful logic chis to use as donors.
I have plenty of 4116s that I know to be good, and an assortment of them to test and mark good or bad.
I think I will soak the sockets and the IC pins in some deoxit and see if they simply aren't making good contact.
FWIW, I have nothing but time right now. I fiddle with these things to fill up the days.