Philips 46PFL5505D/F7 blinking power light no pic no sound

[What?]

Gentlemen, thanks ahead of time for your help and consideration.
I am trying to fix a Philips 46" LCD I fixed about 2 years ago with the help of this forum and it has functioned flawlessly.
I have basically the same problem I had before, pressing either the tv power button or the remote power button does nothing but give a 21 blink power led. No picture, no sound but the cause must be different than the last time because the previous fix is still good.
I have 5v at the PSU/Main boards connector CN2 when I plug the tv in. Upon pressing the power button and with the Main board connector plugged in I get all the voltages shown in the PS schematic, with the Main board unplugged I get nothing, the entire CN2 connector is dead except for a -6v on pin 11 (GND) and the power LED is off. I have removed and tested every component in the area of CN2 and all test good. I have also removed and tested all the components around the T901, except the transformer and the IC (I can't find a datasheet for IC901).
I followed the troubleshooting guide and ended up with 'replace the psu'.
Is it possible to get a 21 blink error code if the ccfls have failed? I can't find a blink code on the internet.
Any help or suggestions would be greatly appreciated.

[ivtec]

Re: Philips 46PFL5505D/F7 blinking power light no pic no sound

Gentlemen, thanks ahead of time for your help and consideration.
I am trying to fix a Philips 46" LCD I fixed about 2 years ago with the help of this forum and it has functioned flawlessly.
I have basically the same problem I had before, pressing either the tv power button or the remote power button does nothing but give a 21 blink power led. No picture, no sound but the cause must be different than the last time because the previous fix is still good.
I have 5v at the PSU/Main boards connector CN2 when I plug the tv in. Upon pressing the power button and with the Main board connector plugged in I get all the voltages shown in the PS schematic, with the Main board unplugged I get nothing, the entire CN2 connector is dead except for a -6v on pin 11 (GND) and the power LED is off. I have removed and tested every component in the area of CN2 and all test good. I have also removed and tested all the components around the T901, except the transformer and the IC (I can't find a datasheet for IC901).I followed the troubleshooting guide and ended up with 'replace the psu'.
Is it possible to get a 21 blink error code if the ccfls have failed? I can't find a blink code on the internet.
Any help or suggestions would be greatly appreciated.

I have fixed mine too ,don't know if same issue ;https://www.badcaps.net/forum/showthread.php?t=48723

[What?]

Re: Philips 46PFL5505D/F7 blinking power light no pic no sound

Thanks ivtec, I saw that post, replacement boards for this TV are hard to come by. I think they are made of unobtainium. I had previously fixed the diode problem but I think this problem is different.

[ivtec]

Re: Philips 46PFL5505D/F7 blinking power light no pic no sound

Thanks ivtec, I saw that post, replacement boards for this TV are hard to come by. I think they are made of unobtainium. I had previously fixed the diode problem but I think this problem is different.

check diode in the pic

[What?]

Re: Philips 46PFL5505D/F7 blinking power light no pic no sound

Yup, I performed that fix on my TV. I used a T220 diode and a heatsink.

[CapLeaker]

Re: Philips 46PFL5505D/F7 blinking power light no pic no sound

does the backlight come on at all?

[What?]

Re: Philips 46PFL5505D/F7 blinking power light no pic no sound

No backlight at all.

[CapLeaker]

Re: Philips 46PFL5505D/F7 blinking power light no pic no sound

Are PSon and BLon present?

[What?]

Re: Philips 46PFL5505D/F7 blinking power light no pic no sound

Capleaker,
PSON = 3.117
BL-SW=0.007
I don't have a BL-ON I think BL_SW is the same thing. The only other BL is BL-Adj.

[CapLeaker]

Re: Philips 46PFL5505D/F7 blinking power light no pic no sound

your main board isn't sending BLon to the PSU to turn on the back lights.

[What?]

Re: Philips 46PFL5505D/F7 blinking power light no pic no sound

Thanks CapLeaker, I was leaning that direction. Now the problem is fixing the Main Board. I have not been able to find a replacement anywhere so I have to fix this board or maybe I should send it out to have it fixed.

[What?]

Re: Philips 46PFL5505D/F7 blinking power light no pic no sound

Nuts, BL-SW goes right to the big processing chip IC3101. According to the schematic there is only 1 resistor R3022 between CN3002 and IC3101 and it checks ok. There is 1 other resistor R3323 that goes to ground and it checks ok. There are no other components between CN3002 and IC3101 for BL-SW.

[budm]

Re: Philips 46PFL5505D/F7 blinking power light no pic no sound

You can/must disconnect the BL-ON wire going back to the main board first and then use 1K pull-up resistor between STBY power suppli pin and the BL-ON pin of the power supply board to see if the backlights will come on when you turn on the TV, if everything on the main board still good then you should get sound and pictures and all the function if there is no other problem with the main board and the T-CON board, if not then you have more than one problem beside the bad BL-ON signal.
BTW, what do you have for the BL-ADJUST (DIMMING CONTROL)? If you have 0V then that is another problem too.

[What?]

Re: Philips 46PFL5505D/F7 blinking power light no pic no sound

budm
I did as you suggested, shorted STBY(5.4V) to BL-SW after removing the connection to the Main Board. The backlights came on but nothing else, no picture, no sound and the power led is still blinking. I measured the BL-ADJ to chassis ground and got -0.007v.
Thanks

[budm]

Re: Philips 46PFL5505D/F7 blinking power light no pic no sound

That means you have more than just bad BL-ON, BL-ADJ problem.
Start checking Voltages on the regulator ICs if the main board has them, may be some fuses too if it also has them.

[What?]

Re: Philips 46PFL5505D/F7 blinking power light no pic no sound

budm,
I found 3 voltage regulators, i attached a photo of the results.

[What?]

Re: Philips 46PFL5505D/F7 blinking power light no pic no sound

budm,
I have not been able to locate any fuses on this Main Board. I have also looked over both sides of the board for any component that looked burnt, broken, cracked, loose, melted or that looks like the magic smoke got out.

[CapLeaker]

Re: Philips 46PFL5505D/F7 blinking power light no pic no sound

Yep, BLon is generated on the main IC. I think that this main board is done for. Only thing you could try is swapping the main IC, EEPROM etc.
When you turn on the TV, does one of the IC's get really hot?

[budm]

Re: Philips 46PFL5505D/F7 blinking power light no pic no sound

budm,
I found 3 voltage regulators, i attached a photo of the results.

They look OK for 1.8V and 3.3V outputs.
It is not going to be easy job figuring out the main board.

[What?]

Re: Philips 46PFL5505D/F7 blinking power light no pic no sound

Thanks CapLeaker and budm for your help. I am kind of stuck, I have not been able to locate another main board, I don't have the equipment to reprogram a eeprom or remove a BGA processor. Maybe I should see if ShopJimmy.com will rebuild this board.