Group, I have two Model 100's with REXs. I changed the batteries on 1 machine, and the screen went blank and will no longer work. My troubleshooting steps so far: 1. Removed REX, batteries, and left the machine off (including the mem switch set to Off)2. All capacitors and the NiCAD backup battery were replaced last year.3. I am getting +5, -5V at VEE and VCD.4. The oscilloscope shows 4.9125 MHz on the crystal and Pins 1 and 2 of the CPU. I am also getting 2.4 MHZ on Pin 36. Pin 37 resets when I press the Reset Button.5. I am also getting activity on the CPU Data Lines.6. I have a RAM+ Unit; I installed ot to see if it would possibly bypass the internal RAM, but that has no effect.7. I did notice that T19 (fuse) was in bad shape, but I believe this will only affect the low battery LED. I researched that this can be replaced using a .25 resistor; I ordered some. Any advice? I am by no means an expert, just enough to get me in trouble.
