Motorola GM140

Controlhead GM160/360/660 Troubleshooting Flow Chart 3-5
2.3 Display
Power Up Alert Tone is OK, volume knob does operate,
indicator/backlight is on but nothing on display
YES
NO
YES
NO
V5 (against 5V)
TP0973 between
-6V and -7V ?
Activity on
Address & Data lines
A0 / D0..D7 / CS1
of U0971?
Check for shortage
U0831 / U0971
Check LCD Assembly
Check / Replace
C0971 / C0973 / R0972
R0973 / R0974 / U0971