Motorola 6864115B62-C

Controlhead GM380/1280 Troubleshooting Flow Chart 3-11
3.5 Keypad Backlight
U0871 Pin 25
is toggling ?
Base of Q0943
> 0.7V ?
Collector of
Q0943
>5V & < 11V
?
Check / Replace
Q0941 / R0955 / R0957


YES
YES
YES
NO
NO
NO
Check / Replace
Q0943 / U0941 / R0941
R0943 / R0949 / R0951

Check for shortage 
U0871

Check / Replace
R0945 / C0943 / R0947

Power Up Alert Tone is audible, volume knob does operate,
display is on but no keypad backlight.