Philips 42pfl5609/98 stuck in standby mode

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Hi all, I have a Philips 42pfl5609/98 TV that can only stay in standby mode after the power is switched on. TV have a steady red standby light but refuses to turn after pressing the on button. Any help would be greatly appreciated.

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Re: Philips 42pfl5609/98 stuck in standby mode

Upon further inspection, I realized that the P802 connector on the power supply board does output a 3.3V on the third left pin(marked as 3.3VSB) when its on with the rest of the pins at 0V when the TV is in standby mode.

[budm]

Re: Philips 42pfl5609/98 stuck in standby mode

3.3VSB should be present the minute you apply AC to the TV.
Since you do have standby Voltage to run the main board, then the main board should send out the P-ON to turn on the rest of the power supply, that P-ON pin DCV should change state when you toggle the power switch.
POWER SUPPLY PCB: 40-IP42CS-PWI1XG

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Re: Philips 42pfl5609/98 stuck in standby mode

Thanks for your reply bdum! After checking the P-ON pin on the power supply board and the main board i realized that there is no voltage reading at either end of the board. How should i proceed next?

[x0clouds0x]

Re: Philips 42pfl5609/98 stuck in standby mode

Thanks for your reply bdum! After checking the P-ON pin on the power supply board and the main board i realized that there is no voltage reading at either end of the board. How should i proceed next?

I took the voltage reading when I pressed the power switch.

[budm]

Re: Philips 42pfl5609/98 stuck in standby mode

You can try verify the power supply function by forcing the rest of the power supply on by using 330 ~ 470 Ohms 1/4W between the 3.3V and the P-ON but you must remove the connector that goes to the main board first. If the power supply is OK then you should see the rest of the switched power supplies come on.

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Re: Philips 42pfl5609/98 stuck in standby mode

Thank you Budm, I tried what you suggested. I measured the bottom 3 pins of p802 connector (marked as 24v) and managed to get 24v output. What should I do next?

[Andrew F. Ali]

Re: Philips 42pfl5609/98 stuck in standby mode

Without connecting the std-by to the BL-ON and connecting the backlights to test if the backlights are working, I would think you have a Main Bd. problem

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Re: Philips 42pfl5609/98 stuck in standby mode

Without connecting the std-by to the BL-ON and connecting the backlights to test if the backlights are working, I would think you have a Main Bd. problem

How can I do that? Do I connect the 3.3VSB to BL-ON?

[budm]

Re: Philips 42pfl5609/98 stuck in standby mode

How can I do that? Do I connect the 3.3VSB to BL-ON?

Yes, with another resistor at the same values as used on the P-ON.
At this point the problem is pointed to the main board.

[x0clouds0x]

Re: Philips 42pfl5609/98 stuck in standby mode

Thanks, Andrew F. Ali and budm! I could get the back light to turn on, so it should be the main board problem. How can I test the main board?

[budm]

Re: Philips 42pfl5609/98 stuck in standby mode

Thanks, Andrew F. Ali and budm! I could get the back light to turn on, so it should be the main board problem. How can I test the main board?

It is complex board so you need to find the schematic diagram that matches your board to troubleshoot down to component level.
You can also try heating and cooling the board and the EEPROM to see if it will make any different.