7 Troubleshooting
CHA42*7L/5**7L
7-3
7-1-3 No Video or Missing Colors
Are 0.7Vp-p video input on
CN201 R, G, B?
Check signal cable and generator.
Yes
No
Are proper waveform on
SK103’s R, G, B cathode?
Refer to 7-2-16 No Video.
Yes
No
Is G2 and heater voltage OK?
Check and replace SK103 and
some parts around it.
Yes
No
Change CRT and replace it.
Check white balance adjustment.
WAVEFORMS
22
19
19
46.4 V (SK103, G)
CH1 P-P = 46.4 V
CH1 RMS = 38.16 V
22
1.016 V (CN202_2, #3)
CH1 P-P = 1.016 V
CH1 RMS = 174.4 mV
WAVEFORMS
17
35.2 V (SK103, G1)
CH1 P-P = 35.2 V
CH1 RMS = 80.84 V
25
4.96 V (IC202, #30)
CH1 P-P = 4.96 V
CH1 RMS = 350 mV
Check signal cable connection, H/V Sync input.
Check Timing mode (14”: 30~55kHz, 15”: 30~61kHz).
Check Cont, Brit key (all Max) and Screen VR (G2).
7-1-4 Visible Retrace
Is G2 voltage (Screen VR) OK?
Adjust Screen VR to 0.4~0.6F/L (back
raster) at cont, bright all max.
Yes
No
Is V_sync input on Q301 base?
Check V_sync input line.
Yes
No
Is proper G1 pulse on SK103’s
G1 pin?
Check
Q301,
C304, C301, D510,
Q504 and around parts.
Yes
No
Check and replace CRT.
25
17
Summary of Contents for CHA4217L
Page 2: ...Samsung Electronics Co Ltd August 1998 Printed in Korea Code No BH68 61127A ...
Page 10: ...Memo 3 Product Specifications 3 4 CHA42 7L 5 7L ...
Page 14: ...5 Disassembly and Reassembly 5 2 CHA42 7L 5 7L Memo ...
Page 62: ...9 Electrical Parts List 9 14 CHA42 7L 5 7L Memo ...