Sony KD-34XBR2 Training Manual page 102

Figure 21-4 provides the step-by-step troubleshooting procedure. Refer to Figure 21-3 for test point location.
Dark Screen. Sound OK.
Is there an IK line
in any CRT?
No
No HV or blanking. Is
one IK line missing?
No
If all IK lines are
missing, the HV may
be LOW or None.
Sample the HV at
CN8016/3 (7.4V) or
D8036/cathode. Is
there voltage?
No
There is No HV. Look
for HV start signals
(Chart 21-1). Suspect
the D board.
Yes
IK
Troubleshoot that
Yes
color C board.
Adj. screen
control first.
Yes
Adj. controls according to service manual.
1. HV is OK.
2. V&H Deflection is OK.
3. IK blanking - Adj. screen control one
at a time to retrace, then back off. Did
the picture come back?
Figure 21-4 - Troubleshooting a Dark Screen
99
21. RA-5A Chassis High Voltage Stage
No
Blanking is caused
by no video output
the A board.
Replace