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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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I have sound and backlights but no picture, i replaced the

Customer Question

I have sound and backlights but no picture, i replaced the tcon and still no picture
Submitted: 3 months ago.
Category: TV
Expert:  Shahid replied 3 months ago.

Hello, I'm Shahid. Sorry to hear that you're having trouble with this but I'll do my best to help.

- Does TV screen stay dark or show any graphics such as volume bar or menu options etc?

Thanks.

Customer: replied 3 months ago.
Screen stays dark (glows)
Expert:  Shahid replied 3 months ago.

OK, turn On the TV and wiggle LVDS cable that connects t-con board and main board.

Do you get any distortion/ lines etc on screen?

Customer: replied 3 months ago.
ok i will try when i get home after lunch
Expert:  Shahid replied 3 months ago.

OK< take your time and reply back with the result.

Thanks.

Customer: replied 3 months ago.
Ok about to go try your suggestion! Sorry for the delay, moving this weekend eeek.
Customer: replied 3 months ago.
no distortion
Expert:  Shahid replied 3 months ago.

OK, can you check 12V on chip fuse located on t-con board?

Also recheck TV model number, UN50EF5000 seems incorrect.

Customer: replied 3 months ago.
How to check the fuse? Model number UN50EH5000FXZA
Customer: replied 3 months ago.
Its a new tcon board tho
Expert:  Shahid replied 3 months ago.

Needs a voltmeter to check volts, set voltmeter to DC volt range, touch black lead to metal frame of display panel for ground connection and use red lead to touch one end of fuse to get reading on meter then touch other end of fuse and get reading. 12V comes from main board so the t-con board can work.

There are different type of t-con board utilized in this model and a sample t-con board image is attached having fuse marked with yellow arrow that will help.

Customer: replied 3 months ago.
would i need to test a brand new icon board 12V fuse?
Customer: replied 3 months ago.
tcon
Customer: replied 3 months ago.
it's a brand new tcon board just installed but same symptoms as old one
Expert:  Shahid replied 3 months ago.

I'm not saying t-con board is bad, just want to check if t-con board is getting 12V power from main board so it can work/ function.

Customer: replied 3 months ago.
I don't have a voltmeter, is there anything else I can try in the meantime till I can get one?
Expert:  Shahid replied 3 months ago.

If 12V is missing then t-con board will not work to send video data to screen internal circuitry. Take your time to get voltmeter for this test, I'm afraid there is no other way around to check volts without voltmeter/ multimeter.

Thanks.

Customer: replied 3 months ago.
Ok I think my friend has one he can bring tomorrow, so what would be the issue if the 12V isn't getting "power"?
Expert:  Shahid replied 3 months ago.

If 12V is not available at t-con board (on both ends of fuse) then suspected part is either LVDS cable (flat ribbon cable) or main board of TV.

If 12V is available at both end of fuse yet no picture appears on screen then display panel (the screen) would be internally defective and causing no picture. Display panel replacement will be required to fix the problem but it would cost more than new TV price of same size so you would be better off with a new TV at that point.

I hope these info will help. If you have any additional questions, feel free to ask. If you're satisfied, please rate me a 5-star at the top of your page.
Thank you.

Customer: replied 3 months ago.
What is more common you think in this three year old tv?
Expert:  Shahid replied 3 months ago.

Main board failure is most common issue and have seen screen internal failure some times but not common.

Customer: replied 3 months ago.
Is there a video of how to test the 12V?
Expert:  Shahid replied 3 months ago.

I'm not sure about it, however, you can search it on youtube with the model number of your TV to see if some one made such video clip.

Customer: replied 3 months ago.
If I have back light LED, does that mean the main board is good?
Expert:  Shahid replied 3 months ago.

Backlight is to illuminate the LCD rear side so viewer can view the image of LCD. Right now we're trying to figure out why no image appears on LCD screen.

Display panel is a package that consist of many things, backlight and LCD screen are contents of display panel.

Customer: replied 3 months ago.
where is it on this icon, I found it on the old tcon
Customer: replied 3 months ago.
I have voltmeter
Expert:  Shahid replied 3 months ago.

Please look at right side of connector of flat cable (LVDS) coming from main board, there is chip fuse labeled as FP1 and YD is written on fuse.

Customer: replied 3 months ago.
ok found it, starting test
Expert:  Shahid replied 3 months ago.

OK, take your time.

Customer: replied 3 months ago.
just plug in tv or turn it on?
Expert:  Shahid replied 3 months ago.

Turn On the TV while touching meter lead on fuse point to get the reading.

Customer: replied 3 months ago.
meter moved both ends, what should it be reading?
Expert:  Shahid replied 3 months ago.

Touch meter black lead to metal frame for ground, set meter to DC Volt range and use red lead to check volts on fuse, expected volts are 12V DC.

Customer: replied 3 months ago.
It reads 12V on both sides of the fuse
Expert:  Shahid replied 3 months ago.

OK, you would need to swap main board of TV to figure out if screen is OK or not. Main board is one where all video inputs are located, please get the part number off of label pasted on main board to search/ google it to get identical replacement main board price info to order it. I hope these info will help. If you have any additional questions, feel free to ask. If you're satisfied, please rate me a 5-star at the top of your page.
Thank you.

Customer: replied 3 months ago.
Ok where would I test on the main board?
Customer: replied 3 months ago.
Or is it replace the main board and if it works then it's solved
Expert:  Shahid replied 3 months ago.

Unfortunately main board can't be tested/ repaired on component level, it is replaceable board for any fault related to it or if the board is suspected, swapping the main board will tell us if screen is fine then you will get picture and if problem persist then screen is internally defective and it would be end of this TV, you would be better off with a new TV instead of spending money and time on this one.

I hope these info will help. If you have any additional questions, feel free to ask.

Thank you.