I suspect that there is a problem with the internal real time clock. I would check if there is a pulse on pin 10. Hard to verify that I will admit.
Basically, pin 10 is the timer pulse on the RST7.5 input to the processor. If you have a problem here your keyboard service routine will be "dead". To me it sounds a bit like a dead x1 crystal at pin 12/13 of the real time clock chil. On Fri, Apr 23, 2021 at 5:40 PM John R. Hogerhuis <[email protected]> wrote: > > > On Fri, Apr 23, 2021 at 1:44 PM Matthew Walworth <[email protected]> > wrote: > >> Thank you for pointing me at that document, John. No luck with the >> procedure fixing the unresponsive keyboard, although it did bring to my >> attention that there is a slight glitch in the upper left corner of the >> LCD. When first turned on, where it should show "Jan" it shows three other >> characters. After being on for a few seconds the "Jan" display appears. I >> also just realized that the clock doesn't start counting up after the >> reset. It should shouldn't it? >> >> > Yes. After a hard reset it should start up in Jan almost immediately (I > think seconds later is significant problem), and the clock should start > counting up. > > -- John. >
