Subj : Re: Advice on the best drive emulator? To : phigan@bbs.penisys.cf From : Robert Roland Date : Fri May 13 2022 10:20 pm On Fri, 13 May 2022 11:52:25 -0000 (UTC), phigan wrote: >a C64 that powers on with just a >black screen The most useful tool for troubleshooting a black screen C64, is the Dead Test Cartridge. Note that a black screen and a blank screen are fundamentally different. Throwing parts at it is a lottery. If you want to continue the lottery, the RAM chips are a very common fault. The bad news is, there's eight of them (or two if you have a later revision). Leave the computer on for a minute or two and check for hot RAM chips. If they get hot, they are definitely bad, but they can also be bad if they are not getting hot. The Dead Test can sometimes tell you which specific RAM chip is bad. Another common problem is the power switch. It switches both the 5 V DC and the 9 V AC. If the 5 V DC is not working, you will get a black screen on the earlier revision (the longboards). Have you checked voltages? That should come before even the Dead Test. -- RoRo --- SoupGate-Win32 v1.05 * Origin: Agency HUB, Dunedin - New Zealand | Fido<>Usenet Gateway (3:770/3) .