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Shahid
Shahid, Technician
Category: TV
Satisfied Customers: 9465
Experience:  I have been repairing electronic gear since 1993 as a qualified Sony tech
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My Philips 40PFL3705D/F7 will not turn on, no picture, no

Customer Question

My Philips 40PFL3705D/F7 will not turn on, no picture, no sound. I have 24v at the inverter and 3.4v at CN1803. I can't find 12v at the fuse on the board that is top center of the set. At that point it appears to register .04v. ?
Submitted: 8 months ago.
Category: TV
Expert:  Shahid replied 8 months ago.

Hello, my name is ***** ***** I'll assist you. I'm sorry you're having trouble with it.
I need additional info to troubleshoot the issue.

- Are you talking about 12V at CN1803 on power board?

Thanks.

Customer: replied 8 months ago.
No, I have 12v at the 3rd & 4th pins on CN1803
Expert:  Shahid replied 8 months ago.

OK, so on what board you're missing 12V?

Customer: replied 8 months ago.
Where I do not find 12v is at F100 on the board above the power supply. I believe that is call the T CON, but I could be wrong.
Customer: replied 8 months ago.
Also there is a clicking coming from the power supply. As long as the power cord in plugged in it clicks intermittently.
Expert:  Shahid replied 8 months ago.

Thanks for the info, that 12V would not available when TV switches Off (either standby mode or protection activates), however, volts may appear for couple of seconds if you unplug TV power cord from wall for 5 minutes to reset, replug back in and press power button, volts may available for a while before the TV shuts Off.

Can you check the volts now?

Customer: replied 8 months ago.
I have pulled the plug and will reply in a few after I plug back in and test it.
Expert:  Shahid replied 8 months ago.

Sure, take your time please.

Customer: replied 8 months ago.
Okay, still nothing at F100. No change from unplugged to plugged in and turned on. I did get a really small voltage that did not change during set above steps.
Expert:  Shahid replied 8 months ago.

OK, since you get output volts at power supply board that means power board is OK and it seems main controller chip internal issue which controls all the functions of TV such as power On-Off, video and audio signal processing etc. This chip is mounted on main board of TV (known as digital board as well) and main board replacement will help to resolve the issue. Please check with following board supplier to get replacement main board..

http://www.shopjimmy.com/catalogsearch/result/?q=40PFL3705D%2FF7

If you are not comfortable working on it yourself then you may please use following link to get list of TV repair shops in area which will help to get repair quote...
http://www.tvrepairpros.com/
I trust my input will help you out. Please feel free to respond if you have any additional questions.
A positive rating to answer would be greatly appreciated, please click on 5 star on this page then click submit/finish button so I can get credit on website for my work. If you don't see rating option then intimate here.
Regards,
Shahid.

Customer: replied 8 months ago.
I have the part on order and it will be a week before it arrive. Can I get back to you once I install the new board?
Expert:  Shahid replied 8 months ago.

Sure, question is open for you, please take your time and reply back with the result.

Please make sure you get identical main board as different version board may not work.

Thanks.

Customer: replied 8 months ago.
Shahid, the new board is in. I now have power on, but I have a blank, blue screen and no sound so far. So, we made progress, but it ain't fixed.
Customer: replied 8 months ago.
no menu on the screen.
Expert:  Shahid replied 8 months ago.

Hi again,

- Does TV stay On with blue screen?

- If so, press menu or volume button on TV, does any graphic appear on screen?

Thanks.

Customer: replied 8 months ago.
No menu, neither by using the remote nor the menu button on the set. Yes it stays on with a blue screen.
Customer: replied 8 months ago.
No graphics at all.
Expert:  Shahid replied 8 months ago.

OK, did you get identical main board having same part number as of old main board?

Customer: replied 8 months ago.
Identical in all aspects.
Expert:  Shahid replied 8 months ago.

OK, is the screen bright blue or dark bluish?

Have you checked LVDS cable runs from main board to t-con board for video data signal that goes inside circuitry of display panel (the screen)?

Customer: replied 8 months ago.
dark bluish. I will have to remove the back this morning to check the connections. I will get back to you in a while.
Expert:  Shahid replied 8 months ago.

OK, dark bluish means screen isn't getting video signal from t-con board and/or t-con board isn't getting video signal from main board so need to check LVDS cable (connecting cable) between t-con board and main board to make sure it is plugged securely and tight.

Please reply back with the result.

Thanks.

Customer: replied 8 months ago.
The cable is tight. I removed it and put it back in tightly and still nothing. The screen is a faint blue, the clicking has stopped and I can now turn the set off and on. Before I had nothing.
Expert:  Shahid replied 8 months ago.

OK, there is another board called FRC board, LVDS cable plugs into FRC board and two flat cables from FRC board go into t-con board that would be located under metal shield. Please provide me picture of rear of TV if there is any confusion locating these boards so I'll mark them for you.

We need to check 12V DC at t-con board at chip fuse labeled as F100.

Customer: replied 8 months ago.
Sorry it took so long.
Expert:  Shahid replied 8 months ago.

Thanks for the picture, so t-con board isn't getting proper working volts, please follow the red wires in harness near the fuse connector that will go into FRC board, do you get 12V at FRC board connector?

If no then please provide another picture of FRC board to see what is going on.

Customer: replied 8 months ago.
No. I find the same small voltage from the red wires all the way back into the FRC board. I do find 12v coming into the FRC board from the power supply.
Expert:  Shahid replied 8 months ago.

Thank you for picture. It means FRC board isn't working and causing the problem. Please replace FRC board in TV that will help to resolve the issue, same/ following supplier would have required FRC board on reasonable cost..

http://www.shopjimmy.com/catalogsearch/result/?q=40PFL3705D%2FF7

Please reply back with the result and if problem resolved then a positive rating to answer would be highly appreciated.

Thanks.

Customer: replied 8 months ago.
Okay, thanks. As you know this will take a few days.
Expert:  Shahid replied 8 months ago.

No problem, I would be more than happy to see this TV up and running again :-)

Customer: replied 8 months ago.
Well the new FRC board from shopJimmy is in the set. All connections are secure and it made absolutely no difference.
Expert:  Shahid replied 8 months ago.

Sorry to hear that, do you get 12V at F100 with new FRC board?

Customer: replied 8 months ago.
No. There was no change after installing the FRC. I have requested a refund from justanswers.com. I cannot continue to put money into this TV board after board. Thank you, ***** ***** authorize my request.