I would start checking the signals at the LCD connector. Ensure the voltages are present, and that the contrast signal is also there and adjusting well.
Sometimes if you hold the screen at different angles you can see faint text. Give that a try. Seems like you m100 is mostly working... On Monday, August 19, 2019, [email protected] < [email protected]> wrote: > Hello, > > New to the list. Just pulled my Model 100 out of storage where it had > been for at least 20 years. > > It would not power up so I have replaced many of the electrolytic > capacitors (several of which were obviously leaking) including all the ones > near the power switch (C83, C82, C85, C84, C90, C86, C92) and also four > 10uF caps over nearer the modem switches (C49, C50, C54, C55). > > It will now power up but there is no display. > > I know it is powering up because I am able to blindly go into Basic and > type "beep" and the speaker beeps. This also proves the keyboard is > working. > > I am powering with four fresh AA batteries. > > I've tried adjusting the contrast knob. I've tested the NiCD battery and > it is showing 4.4v. > > I've tested VDD (+5v), VB (+5v), and VEE (-5V) and all test solidly good. > > Ribbon cable has been reseated and looks good. > > When I do a Reset, I can hear a slight click from the speaker so that > button is working. I have tried doing a cold reset > (control-shift-break-reset) and still no display. > > When I power off, the battery LED flickers quickly so that is working. > > What would be my next steps? Is there a good place on the LCD to test to > make sure it is getting good power? If so, where? > > Thanks in advance, > Chad > > >
