7 Troubleshooting
7-16
CHA42*7L/5**7L
Are full white and white
square luminance almost
same?
No
No
Does full white luminance vary,
adjusting ABL step with Softjig?
Yes
Is R121 right as CRT’s
differential items?
Yes
No
Yes
Does the voltage of
IC101’s Pin 8 vary between full
white and No Video?
Yes
No
Does the PWM duty of
IC202’s Pin 21 vary adjusting
ABL step?
Yes
No
Display the full white pattern.
Replace it.
Check and replace IC101.
Does T501’s Pin 8
voltage vary between full white
and No Video?
Yes
No
Check and replace D518, IC101.
Are 12 V line, R504, L504, Q501
and Q518 ok?
No
Yes
Replace it.
Are C509, D514, Q502 and Q506
ok?
No
Yes
Replace it.
Check and replace T501 and CRT.
Check and replace IC202 and
around parts.
Replace R121 to higher or lower
one that meets the spec.
Check connections between
CN202 and CN202_2.
7-2-14 ABL Failure
Symptoms : – Full white luminance is too bright. (ABL minium is over 35 F/L)
– Full white luminance is too dark. (ABL maximum is under 35 F/L)
– The luminance of full white and No Video are almost same.
F/W: 4.1~4.3V
No Video: 5.3~6.0V
F/W: 1.5~3.0V
No Video: 5.5~7.0V
Содержание CHA4217L
Страница 2: ...Samsung Electronics Co Ltd August 1998 Printed in Korea Code No BH68 61127A ...
Страница 10: ...Memo 3 Product Specifications 3 4 CHA42 7L 5 7L ...
Страница 14: ...5 Disassembly and Reassembly 5 2 CHA42 7L 5 7L Memo ...
Страница 62: ...9 Electrical Parts List 9 14 CHA42 7L 5 7L Memo ...
Страница 64: ...Memo 10 Block Diagrams 10 2 CHA42 7L 5 7L ...