Nokia 920C Service Manual page 21

5-1-12 V Size or Pos. Variation Failure
IC261 Pin 23 output varies with
different DAC values?
Yes
Check and replace IC261 and IC301.
5-1-13 High Voltage Failure
Q524 gate driving pulse exist?
Yes
Done
720C/920C
No
Check some parts around IC301.
Check bias voltage.
Check +12 V line.
No
Check and replace Q521, Q522, Q523,
Q524 and IC501.
5 Troubleshooting
5-7