I believe it is CTRL-BREAK-RESET. Also to state the obvious, try adjusting the contrast control on the screen.
> On May 17, 2019, at 9:38 AM, Jeffrey Birt <[email protected]> wrote: > > Make sure the memory power switch is ON. Then, you’ll need to do a hard > reset, I think the ley combination is holding down control-shift and then > pressing the reset button. Hopefully someone else will chime in if that is > wrong. > > Jeff_Birt > > > From: M100 <[email protected] > <mailto:[email protected]>> On Behalf Of Ed Graffius > Sent: Friday, May 17, 2019 8:26 AM > To: [email protected] <mailto:[email protected]> > Subject: [M100] Have a question about my M100 > > I just picked one up last monday at an estate sale. New, in the box, but > opened. lack of ANY fingerprints, wear etc leads me to believe got it, > looked at it, lost interest fast. > > I put in 4 new AA batteries...no joy. I have the new manual, and I found the > service manual online and poured thru it. > > So here we go: TRS80 M100 serial 306005812 > > Have not opened it yet. > > I would assume the nicad is long dead and is likely 'reaction complete' > meaning it has no chance of charging. I did not get the power supply (nor > was I looking for one at the auction, but part 2 is this monday so I will) > > I have ample power supplies I can rig up. > > I note it says tip negative - common to RS equipment - whereas the rest of > the planet preferred tip positive. But again, I can dream up the correct > polarity. > > I suspect due to age and perhaps accidental power reversal, the oscillator > used to produce the board +/- DC could be faulty, and I have the proper tools > to probe it and test it. > > From looking at the SCM, if it was reversed polarity, small chance this > translates to the chipset as the PS/battery box is isolated thru the > transformer and reversal would have reverse biased the transistors. perhaps > dried caps on the timing circuit? dunno yet. > > When I turn if off, for a small half second the low batt light flashes, but > that light is driven from a narrow voltage divider and would be expected. A > couple times on power on if I press many keys, I get beeps from keys. faulty > virgin display? > > Any ideas where to start? > > thanks!
