After contemplating things overnight, I pulled the battery and T18 this morning. I pulled T18 by mistake as I thought it was T20. I was after T20 as it is responsible to the auto power down and it will also work without the memory battery. This did no good.
I then realized had not pulled T20 so I then pulled it and magically had +5V and -5V back! I checked T20 and it was fine and I ohmed at all the connections to it and they were fine. I soldered it back in and still had +5/-5. I can only guess there must have been a piece of schmaltz across the leads I could not see. I did a hard reset and it will beep when ‘beep’ is typed in, but the display is blank. But at least it is progress. BTW, you can get small DC-DC converters with a remote off input. Jeff Birt From: M100 <[email protected]> On Behalf Of Josh Malone Sent: Monday, July 6, 2020 8:04 AM To: [email protected] Cc: Model 100 Discussion <[email protected]> Subject: Re: [M100] M100 switching power supply troubleshooting I too have an M100 with weird power supply issues. I'm seriously contemplating designing a replacement M100 SMPS for cases like these. Would not be as simple as finding an OTS module though, if we want the software power control to keep working. :-/ I have had to replace the xfmr in one machine I got in for repair. I'd love to find a suitable replacement for that part as well. I haven't gone to the length of measuring a known-good one yet though. Have you tested the inductance of the xfrmr yet? -Josh
