The first things to do when troubleshooting any M100 problem is to check that the power supply is functional. There are test points on the board that indicate "Vee" which is the negative 5v supply.
The slides from my TASM 2019 talk go into a lot of detail on this: https://www.vintageboot.net/2019/09/tandy-assembly-talk-m100-repairs/ On Thu, Nov 4, 2021 at 3:19 PM George Goodman <georgeogood...@orgoodman.net> wrote: > > Hi all, > > My M100 display seems to have taken a turn for the dim. See the images in > this shared folder —> > https://www.dropbox.com/sh/y1cpftct6dgqy2j/AAAEb3PmIC1b30qh7FV_WX4ea?dl=0 > > I can’t point to anything that happened. I started an install of TS-DOS from > my Backpack and, once the Initial Program Load began, stepped away from my > desk to get a glass of water. When I returned a few minutes later I thought > the M100 had flat out died. I removed the Backpack and tried turning the M111 > on and off and even did a hard reset. No joy…I thought. > > I happened to sit down at my desk and catch a more extreme viewing angle of > the display. That’s when I realized that there was just a display issue. I > verified that I can start up Basic, make the system beep, open Text, etc. > However, I haven’t found anything that will get the display back to good > viewing from overhead. > > BTW, I did try the contrast dial and that didn’t have any impact. The images > in that shared folder were taken with the contrast at its highest. > > Does anyone have suggestions for debugging and fixing this? > > Thanks, > > george g.
