Abnormal Sound (Tv)-Main Pcba - LG 22LN4050 Service Manual

8. Abnormal sound (TV)-Main PCBA

Abnormal sound (TV)
1
Put into RF cable completely?
2
Is 1.8V at 7pin of TU401?
3
Is I2C waveform
At 3,4pin of TU401?
4
Is IF waveform at 43
,44 pin of IC501?
Change Main PCBA
WAVEFORMS
3
3Pin of TU401 (SCL)
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Only for training and service purposes
NO
YES
NO
NO
NO
4Pin of TU401 (SDA)
insult RF cable tight and then
If 1.7V is not at plus pin of TU401, check
It is over 3V at 2pin of IC401,
if it is not, Check Line between TU401
and IC401 is open or short.
Another is change IC401 or TU401
Check Line between TU401 and IC501
is open or short, Another is change
Check Line between TU401 and IC501
is open or short, Another is change
4
43,44pin of IC501
- 20 -
Cable nut screw tight.
IC501 or TU401
IC501 or TU401
LGE Internal Use Only