5.1V ----- Original Message ----- From: Ed Graffius To: [email protected] Sent: Friday, May 17, 2019 11:24 AM Subject: Re: [M100] Have a question about my M100
just in case D14 is bad anyone got the spec on the zener? I cannot read it clearly off the SCM. I got a few 4.5 and a ton of 5.2 in stock... -----Original Message----- From: Josh Malone <[email protected]> To: m100 <[email protected]> Sent: Fri, May 17, 2019 11:10 am Subject: Re: [M100] Have a question about my M100 Service manual specifies Vee failure as indicating components D15, C85, and D14. On my most recent Vee failure, C85 was leaking and D14 was physically broken. On Fri, May 17, 2019 at 11:06 AM Stephen Adolph <[email protected]> wrote: > > probably the capacitor on the -5V rails is a problem here. fix -5V and you will get a display again almost certainly. > > If +5V is working then the switching supply itself is functioning. > > I have machines with this symptom also, if a fix is identified please share. I have never recapped an M100 . Maybe I should be. > > > On Fri, May 17, 2019 at 10:32 AM Josh Malone <[email protected]> wrote: >> >> On Fri, May 17, 2019 at 10:22 AM Ed Graffius <[email protected]> wrote: >> > >> > ok, opened it up and the nicad has 4.8ish volts on it. >> >> Good. I'd plan to remove or replace it soon anyway. >> >> > Theory: lack of -5v prevents the LCD from lighting up? >> >> Yep. Check out the M100 service manual >> (https://ftp.whtech.com/club100/doc/m100ServiceManual.pdf) for >> troubleshooting steps on the power supply. It's a great reference. >> >> > >> > btw - the <enter>, 'B''E'E'P' <enter> works, so that means the CPU is CPUing? >> >> Yep. Display issues only. Should be a simple fix. Congrats on your acquisition. >> >> -Josh
