Thanks Erik, I'll try your suggestions. Clint
On Fri, Dec 19, 2025 at 9:51 AM Erik Keever <[email protected]> wrote: > Hi Clinton, > > Get the M100 service manual PDF online, it will have steps for checking > the internal power converter. It is a discrete set of transistors, not an > SMPS chip, and I have read in at least one place that it is not known for > being particularly reliable. > > A quick check, the upper left of the board is the PSU area and you should > be able to find ground, VCC (+5) and VEE (-5) test points. > > -- Erik > > On Thu, Dec 18, 2025, 10:10 PM Clinton Reddekop < > [email protected]> wrote: > >> Hello all, >> >> My Model 100 has broken somehow. I'm hoping for some advice either on >> troubleshooting or somewhere I could send it for repair. >> >> >> My model 100 was on, I think in the BASIC screen but not running a >> program. I turned away for a few minutes and when I turned back around >> there was nothing on the screen. It was running from an AC power adaptor. >> I have checked it with a multimeter - it is 6V. >> >> Turning it off then on again didn't work. >> >> Turned it off and removed my REX module just in case. Still nothing when >> turned on. >> >> Turned it off. Removed QUAD RAM module. Split the case and put back an >> original 8K module in the base location. Still no workie. >> >> I have tried running from batteries. I have tried reset. I have tried >> holding ctrl and break while turning it on. I have tried turning it on, >> pressing <enter>, beep<enter> - it doesn't beep. >> >> Adjusting the contrast dial makes all the pixels darken a bit, just as it >> would normally do for pixels that aren't on. But the screen has no pixels >> that are on. >> >> >> Any help is appreciated. >> >> Thanks, >> Clint >> >
