OK they look good. The VB = +3.6V (approx) when powered down, it is the backup voltage for the RAM.
It would appear that all the voltages are correct. The next step would be to start tracing out the address, data and control lines to make sure the buffers etc are all working when the unit is powered on. Hope to find a buffer that does not work or other failed chip or even a failed joint. It can be done with a MM but not easy. A cold boot might be worth trying if you have not already done so. ________________________________ From: M100 <[email protected]> on behalf of Greg Swallow <[email protected]> Sent: Tuesday, June 5, 2018 04:07 To: [email protected] Subject: Re: [M100] Model 102 Black Nothing After Y2K ROM install I got VDD +5VDC, VEE -5VDC, and VB of +5VDC. No 3.6VDC on VB. ----- Original Message ----- From: "Fugu ME100" <[email protected]> To: [email protected] Sent: Monday, June 4, 2018 7:06:33 PM Subject: Re: [M100] Model 102 Black Nothing After Y2K ROM install It does sound like there might of been some static damage on the board. The ROM shares lines with the RAM wonder if a RAM has fried? Or a buffer? On the M100 the Vdd, Vee, Vb and GND lines are marked so it is quite easy to check the +5, -5V & +3.6V are on the board OK.
