Nokia 920C Service Manual page 22

5 Troubleshooting
5-1-14 ABL Failure
Input full white pattern to monitor.
IC101 (17": IC104, Pin12) Pin 15
input exists and
varies with different patterns?
No
Check CN102.
T501 Pin 8 output exists?
Yes
IC103 (17": IC04) Pin 16 output
exists and varies with different
patterns?
Yes
Check and replace Q101,
Q102 and +12 V line.
5-1-15 Dynamic Focus Failure
IC261 Pins 18 and 15 output
10
are right?
Yes
Some parts around Q551,
Q552, Q553 and Q554 are right?
Yes
Some parts around T502 are right?
11
Yes
Check the connection between FBT
Pin 13, CRT Socket PCB.
5-8
Yes
Check and replace IC101 (17":IC104) .
No
Check and replace T501.
No
Check and replace IC103 (17": IC04).
No
Check and replace IC261.
No
Replace failed part.
No
Replace failed part.
WAVEFORMS
2.20 V (IC251, #15)
10
CH1 P-P = 2.20 V CH1 RMS = 2.776 V
11 580 V (T551, #1)
CH1 P-P = 580 V CH1 RMS = 278.2 V
720C/920C