NO POWER
Before troubleshooting for No power, make sure that AC power is present at the input of the power board and all the sockets are plugged securely.
Switch ON the set. make sure the presence of AC of 100-240V is normal.
If OK, Check if Pin 3,4 of CN701 are 5V. If no voltage detected, check the power board.
If there is 5V at CN701, measure U701 pin 2 = 3.3V, U702 pin 2 = 1.8V. If there is no voltage, check and replace U701,U702. If these voltages are present;
Check if X401 oscillate waveform are normal. If not, replace X401. If X401 oscillates normally, and there is no voltage, check U401.
NO PICTURE
Check if pin 3,4 of CN701 are 5V input. If there is no voltage, check Power Board. If there is voltage;
Measure U701 pin-2 = 3.3V, U702 pin 2 = 1.8V. If no voltage detected, replace U701, U702.
If these voltages are present, check X401 oscillate waveform are normal. If not, replace X401.
If X401 oscillations are not normal, replace X401. If it is normal;
Check U401. In found not normal, replace U401. If found OK;
Check if sync signal from computer is output and video cable is connected normally. If any abnormality is detected, replace the Cable.
