Keypad Backlight - Motorola 6864115B62-C Detailed Service Manual

Controlhead GM380/1280 Troubleshooting Flow Chart
3.5

Keypad Backlight

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