I should have added that the reason I suspect the one RAM module soldered to the board is that I tried removing the other 3 (this has all 32K of memory installed) and nothing changed. My next step was to desolder the RAM module, install socket strips and then try one of the other RAM modules in the main slot.
I am also planning to try taking the ROM from my working M100 and installing that in the non-working unit to see if it is the ROM. Any other ideas would be appreciated. Scott M. From: Scott McDonnell Sent: Wednesday, December 16, 2020 8:06 PM To: m...@bitchin100.com Subject: [M100] Model 100 Repair - Keyboard not responding,LCD missing a column I mentioned before that I bought two Model 100s and that one of them is not working. Here is a description: The computer boots sometimes. When it doesn’t you get just a dark screen. Turning on and off a few times, you get the menu. However, only Schedule is populated (in the first slot which would normally be BASIC…) and there is no “SELECT” at the bottom. No response from any keyboard keys. The above leads me to believe that it is not really that the keyboard is not working, but that the computer encounters a fault while loading the menu and never completes to the point that I could use the keyboard. That leads me to think maybe a faulty ROM or possibly the one RAM module that is soldered to the board. I wonder what others might think? Second problem: The LCD is missing a column. I got brave and disassembled the LCD to clean the contacts. The good news is that I think I fixed that missing column. The bad news is that now the LCD is all jumbled mess. I don’t think it is alignment since some text displays perfectly fine is just the right spots. I think it is a lack of pressure. Planning to install some thin foam inside the metal surround to create more pressure on the LCD contacts. I think the metal twist tabs are just not cutting it anymore. I will update whether this works or not. I plan to recap both of these and replace the NiCad batteries, but I don’t believe that either of them currently have any issues with those parts. If anyone has experienced the above problem, I would very much like to hear what you have done to fix it. Scott M.
