Sony Bravia KDL-55EX713 - No picture

[chlanman]

Hello, gents im having a problem with my KDL-55EX713
Screen started going bad with lines on the left hand side only.
Then gradually went to the full screen. Then went washed out, and then completely black now.
This was over about 2 hour period.

Now if i turn it on, just a black screen.

Could this be the t-con ? I visually looked at the power supply board and all the cap's look to be good. When i turn power on there is a click

Any suggestions?
Where can i find schematics for my model?
Thanks guys!!

[tibimakai]

Re: Sony Bravia KDL-55EX713 - No picture

I would check the voltage, before and after the fuse on the T-con.

[chlanman]

Re: Sony Bravia KDL-55EX713 - No picture

Thanks.
Where do i check this?Wheres the fuse on the tcon? And what should the voltage be?

Thanks!!

[chlanman]

Re: Sony Bravia KDL-55EX713 - No picture

Here's the tcon board from my TV.
Where can i find the fuse?
Thanks

[sordids999]

Re: Sony Bravia KDL-55EX713 - No picture

Thats your fuses circled in red

[chlanman]

Re: Sony Bravia KDL-55EX713 - No picture

Thanks guys!
And if its OK, what would you suggest next?

[budm]

Re: Sony Bravia KDL-55EX713 - No picture

"And if its OK, what would you suggest next?" Well we do not know the result yet until you check the fuse and the voltage first before going further.
If there is no voltage (mire likely to be 12VDC) on the fuse, then you will need to do indepth component level troubleshooting the main board.

[chlanman]

Re: Sony Bravia KDL-55EX713 - No picture

"And if its OK, what would you suggest next?" Well we do not know the result yet until you check the fuse and the voltage first before going further.
If there is no voltage (mire likely to be 12VDC) on the fuse, then you will need to do indepth component level troubleshooting the main board.

Thank you.
So first thing check the fuses to confirm they are ok
Plug in the tv turn on and confirm there is +12v to the fuses?
Thanks for the help, im a n00bie

[budm]

Re: Sony Bravia KDL-55EX713 - No picture

Yes.

[chlanman]

Re: Sony Bravia KDL-55EX713 - No picture

Thank you.
Measuring the voltage on the board with the power on. Do i check the fuse end to end with multimeter on VDC?
Or do i check with one end on the fuse with other to a ground point ?

[Neelix]

Re: Sony Bravia KDL-55EX713 - No picture

With the power on and your meter set to Vdc, with the black probe you touch against a ground point and with the red probe you touch against one end of the fuse, check the voltage reading on your meter and then with the red probe again you touch against the other end of the fuse and again check the voltage reading on your meter. First though measure the end to end continuity/resistance of the fuse, with the power off

[chlanman]

Re: Sony Bravia KDL-55EX713 - No picture

Completed some checks

1) All fuses have continuity, no concerns
2) All fuses have +12~vdc at fuses

Now i noticed when i turned it on there's a clicking coming from the tcon board
Im assuming this isnt normal ?

[budm]

Re: Sony Bravia KDL-55EX713 - No picture

It is down to either bad panel or bad T-CON. There are flat cables between the panel and the T-CON board, you can have them connected one at a time to see what you will get on the screen.

[chlanman]

Re: Sony Bravia KDL-55EX713 - No picture

Thanks.
Checked with 1 connected at a time. Basically gives me horizontal lines on either left or right side with one connected.

What would "click" on the Tcon board constantly?

Sorry but whats a bad panel? If its a bad panel is the tv pretty much scrap?

Thanks

[budm]

Re: Sony Bravia KDL-55EX713 - No picture

"Sorry but whats a bad panel? If its a bad panel is the tv pretty much scrap?"
If you have both cables disconnected, do you still hear clicking sound?

[chlanman]

Re: Sony Bravia KDL-55EX713 - No picture

"Sorry but whats a bad panel? If its a bad panel is the tv pretty much scrap?"
If you have both cables disconnected, do you still hear clicking sound?

I will check that when i get home, thanks.

Im not sure what the cables exactly do?

What do cables 1,2,3 exactly do ?


Thanks

[budm]

Re: Sony Bravia KDL-55EX713 - No picture

1 & 2 goes to drive the ICs on the flexible between the glass panel and the PCB where the tab bonding are made. #3 is the LVDS cable where the LVDS are from the main board, it also supplies the power to the T-CON board.
https://www.badcaps.net/forum/showpo...1&postcount=16
https://www.badcaps.net/forum/showpo...4&postcount=12

[chlanman]

Re: Sony Bravia KDL-55EX713 - No picture

Sorry as said before im a n00b and still learning lots

What is ICs, PCB, LVDS ?

Thanks again for all the help

[budm]

Re: Sony Bravia KDL-55EX713 - No picture

Just type in the search engine.
'What is Integrated circuit'
'what is PCB'
'what is LVDS'

[drussell]

Re: Sony Bravia KDL-55EX713 - No picture

Sorry as said before im a n00b and still learning lots

What is ICs, PCB, LVDS ?

Everyone has to start somewhere!

IC = Integrated Circuit (a chip)

PCB = Printed Circuit Board (a board)

LVDS = Low-Voltage Differential Signaling (a common way of connecting things like the actual display panel)

For high speed signals you often engineer things so that there is a pair of signal wires for each required signal. One swings positive while the other swings negative. The difference between those two signal wires is the actual signal value. Any noise that is introduced to the pair is present on both signal wires, so after the subtraction at the end, the noise is removed and the clean signal remains.

This is why various types of wiring are twisted pair...
It keeps the two differential signals tightly coupled so that any noise introduced is equal on both wires and can be removed at the end.

Microphone cables work this way... "Twisted Pair" network cables work this way...

LVDS is a specific type of differential signalling that happens to be the way LCD panels and such are connected to their controller boards to keep those high-bandwidth signals clean and tidy on the jaunt over to the actual panel.

http://en.wikipedia.org/wiki/Low-vol...tial_signaling