You have the correct Voltages but it is missing the BL-ON signal from the main board to turn on the backlights circuit, the power supply board may have pull-up resistors for the control signals pins to allow self test of the power supply board, do unhook the cable from the power supply board to the main board then pug the TV into the outlet to see if the backlights will come on and stay on as long as the TV is plug in or not.
If the backlights do not come on then you need to report the Voltage readings on that connector of the power supply board again (without it connecting to the main board), the reading will tell us if the power supply board has pull-up resistors or not.
You have any dark lines spanning horizontally in the screen?
Just fixed one of these suckers the other night. 3 bad CCFL tubes. Usually represented with picture may or may not come on briefly but you can see with a flashlight. This model probably has pull up resistors so the CCFLs will come on if you disconnect the main board from the power supply.
If it does not look towards an inverter or CCFL failure.
BTW, your power supply board is not the typical power supply-inverter combo board.
The board has the Inverter transformer driver circuit with MOSFETs on the power supply board, they supply high frequency AC to connector CNI801 pin 3 (LOW 193VAC) and pin 1 (HIGH 373VAC) of the power supply board to drive the Primary winding of the Inveter transformers on the Inverter transformer board, CNI801 also supplies 12VDC (which you report as present) to run the protection circuit on the Inverter transformer board.
Please check the DC Voltages on those connector pins again (without the cable going to the main board in place), the readings will tell us if it has pull-up resistors for self test or not.
No scorch marks. 450v caps read 375v. Everyone is talking about standby mode; on this t.v. , when is off, the indicator light stays red and I have no readings. If I turn it on, it chimes, the light flashes and then goes off. After several minutes, it shuts off.
I have a ln40c650, seems like normal operation is solid red standby light while off , when I turn it on I get 5 blinks then it goes off, the standby light that is. seems to be working fine.
You have any dark lines spanning horizontally in the screen?
Just fixed one of these suckers the other night. 3 bad CCFL tubes. Usually represented with picture may or may not come on briefly but you can see with a flashlight. This model probably has pull up resistors so the CCFLs will come on if you disconnect the main board from the power supply.
If it does not look towards an inverter or CCFL failure.
You have the correct Voltages but it is missing the BL-ON signal from the main board to turn on the backlights circuit, the power supply board may have pull-up resistors for the control signals pins to allow self test of the power supply board, do unhook the cable from the power supply board to the main board then pug the TV into the outlet to see if the backlights will come on and stay on as long as the TV is plug in or not.
If the backlights do not come on then you need to report the Voltage readings on that connector of the power supply board again (without it connecting to the main board), the reading will tell us if the power supply board has pull-up resistors or not.
You have any dark lines spanning horizontally in the screen?
Just fixed one of these suckers the other night. 3 bad CCFL tubes. Usually represented with picture may or may not come on briefly but you can see with a flashlight. This model probably has pull up resistors so the CCFLs will come on if you disconnect the main board from the power supply.
If it does not look towards an inverter or CCFL failure.
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