LG 22MT45A - Page 15

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Only for training and service purposes
4. Abnormal screen (TV)-Main PCBA
Put into RF cable completely?
Abnormal screen (TV)
YES
NO
NO
insult RF cable tight and then
Cable nut screw tight.
1
Change Main PCBA
WAVEFORMS
Is 1.8V at 7pin of TU401?
2
Is I2C waveform
At 3,4pin of TU401?
3
4
Is IF waveform at 43
,44 pin of IC501?
NO
NO
3
3Pin of TU401 (SCL)
4Pin of TU401 (SDA)
4
43,44pin of IC501
If 1.7V is not at plus pin of TU401, check
It is over 3V at 2pin of IC711,
if it is not, Check Line between TU401
and IC711 is open or short.
Another is change IC711 or TU401
Check Line between TU401 and IC501
is open or short, Another is change
IC501 or TU401
Check Line between TU401 and IC501
is open or short, Another is change
IC501 or TU401