No -12V
YES
Is the voltage 0f
C932 -13V
YES
Is the IC155 pin2
12V?
YES
Check or Replace the Q942
No VF+
YES
Is the ZD950
Normal?
YES
Replace the R993 or Q950, Q943
NO
Check or Replace the D970
NO
Check the PWR CTL
"H" signal from µ-com
NO
Replace the ZD950
3-3