I just checked the +5v and -5v at the display connector on the motherboard and 
also at the connector on the display and both are good.  I also checked the 
contrast signal and it is adjusting with the contrast pot.
So it seems that solid power is at least making it to the LCD... however, there 
is no display at all no matter what angle/lighting I use.
Thanks,Chad


    On Monday, August 19, 2019, 08:47:06 PM CDT, Stephen Adolph 
<twospru...@gmail.com> wrote:  
 
 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, chadhendrick...@sbcglobal.net 
<chadhendrick...@sbcglobal.net> 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


  

Reply via email to