Troubleshooting - Samsung CHB5707L/5237L Service Manual

7 Troubleshooting

7-1 Parts Level Troubleshooting
Notes: 1. If a picture does not appear, fully rotate the brightness and contrast controls clockwise and reinspect.
2. Check the following circuits.
• No raster appears: Power circuit, Horizontal output circuit, H/V control circuit, and H/V output circuit.
• High voltage develops but no raster appears: Video output circuits.
• High voltage does not develop: Horizontal output circuits.
7-1-1 No Power Supply
Check and replace FH1, D602,
D603, D604, D605.
Chirping noise exists?
No
Repeating start?
No
IC601 Pin 1 waveform is right?
1
Yes
OP601, IC603, D610 are right?
Yes
Normal operation
Yes
Verify voltages.
Yes
Done.
CHB5**7L/6**7L/7**7L
Yes
Check and replace IC601.
Yes
Check and replace D607.
No
Check and replace OP601, IC603,
D610, D624, D609.
No
Replace parts and verify voltages.
No
Replace Main board.
WAVEFORMS
1 544 V (IC601, #1)
CH1 P-P = 544 V CH1 RMS = 332.4 V
7-1