---------- Forwarded message --------- From: Charles Hudson <[email protected]> Date: Mon, Oct 19, 2020 at 9:08 AM Subject: Model 100 Boot Issue? To: <[email protected]>
Stephen, Thank you again for your responses. You pointed to M28 (an MN4013B flip-flop on my board) as an indicator of a shutdown signal. I tested M27 (an MN4011B 4-output NAND) and M28. Neither has positive voltage at pin 14, and M28's pin 13 actually measures a few tenths less than 0VDC. The choke and ferrite in the leads from the jack are OK; 8.06 VDC arrives at the board and approximately this much makes it to the power switch. I checked the reset switch to see if it was shorted but it does not appear to be so. This may take me forever but at least it keeps my mind off my poison ivy rash. Thanks again, -CH- Afternote: The zero voltage on M27 and M28 occurs when the memory backup battery switch is "off". If I repeat the measurement with it "on" I get 2.13 VDC or so, whihc I have assumed is the contribution of the memory backup battery. Rule #1: Don't assume?
