Beep test does not work on either unit.
On Sat, May 25, 2019, at 6:39 AM, Josh Malone wrote: > Does the no-screen BASIC test work? (Cold-start, enter, B E E P, enter) > > On Sat, May 25, 2019, 8:22 AM Stephen Adolph <twospru...@gmail.com> wrote: >> Kurt, do you have a scope? >> I would certainly try reseating any socketed parts. Main rom is socketed for >> sure. >> Then I would start at the clock and work forwards. >> * verify the CPU has clock >> * verify the CPU control lines are toggling >> * look at the address and data lines for toggling and level >> >> if that all looks ok then, pin by pin on the main rom, check for toggle and >> level. >> again for the ram modules. >> to make it easy remove as many ram modules as you can. >> >> check DC on the power supplies of course. >> >> On Fri, May 24, 2019 at 8:41 PM Kurt McCullum <ku...@fastmail.com> wrote: >>> __ >>> I've got two NEC 8201s that are both dead. I'd like to get them up and >>> running again. Especially the one with the Japanese keyboard. Has anyone >>> put together a list of what to check to diagnose where the problem might >>> be. I have done the power supply test from the service manual and the CPU >>> seems to be correct but I'm not sure where to start. Both units turn on >>> with a blank screen. >>> >>> Kurt
