Thanks for the info!
Will check!
Measure the -5V supply rail. It could be low because the RS232 level shifter chip has faults. Also check the +5V and -5V at the LCD itself to rule out a connection issue (bad joint at connector or leading to connector).
Jeff Birt
-----Original Message-----
From: M100 <[email protected]> On Behalf Of ExPLIT | Pawel Radomychelski
Sent: Friday, April 16, 2021 2:20 PM
To: [email protected]
Subject: [M100] NEC PC-8201 adjusting contrast doesnt work
Hello collegues.
I got an Japanese NEC PC-8201.
While its working, i can't adjust lcd contrast.
I tried already change lcd and power board, but it didnt help.
Problem is somewhere on the mainboard.
I removed the round black part for ajusting lcd contrast, cleaned it and put back on.
Didn't help.
Sometimes i see also small flimmering, lcd is getting a bit darker and than back to normal.
Did somebody had the same issue?
Thanks
--
Kind regards / Mit freundlichen Grüßen
ExPLIT IT Soltions
Pawel Radomychelski
