I am working on a few sets that the backlight lights up but no picture how can I determine if its a bad main or tcon?
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Re: how to determine if its a bad main or tcon?
Add panel to that too. No picture can also be caused by a bad panel. I usually begin by disconnecting the ribbon cables which connect the Tcon to the panel address boards. Do one at a time and cycle power. If you get a picture on one side, your main board is good and the problem is likely the panel.------------signature starts here------------
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Re: how to determine if its a bad main or tcon?
take a 100Mhz oscilloscope and look at the LVDS signal that goes from the main board to the tcon. Flick the menu button on and off and you should see the signal changing in the oscilloscope.
Sometimes disconnecting one cable at a time from the tcon to the panel wont work. At least it didn't on the last 60" Samsung that I fixed.
Do some research of your TV model number at SJ for instance.
Also check the fuses on the tcon!Comment
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Re: how to determine if its a bad main or tcon?
i dont have a scope. and what about sets that just have 1 ribbon to panel and screen lights up but no picture how can you determine then if its tcon or main?Comment
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Re: how to determine if its a bad main or tcon?
You can start by at least checking the DCV feeding the T-CON, then there are 2~3 switching power supplies on the T-CON and regulator ICs which you need to test the Voltages. If some of the Voltages are not present, then disconnect the ribbon cable/s between the T-CON and the panel to see if the Voltages come back. Most of the T-CON boards have test points for testing the Voltages.
https://www.badcaps.net/forum/showpo...&postcount=202Last edited by budm; 08-11-2015, 10:14 PM.Never stop learning
Basic LCD TV and Monitor troubleshooting guides.
http://www.badcaps.net/forum/showthr...956#post305956
Voltage Regulator (LDO) testing:
http://www.badcaps.net/forum/showthr...999#post300999
Inverter testing using old CFL:
http://www.badcaps.net/forum/showthr...er+testing+cfl
Tear down pictures : Hit the ">" Show Albums and stories" on the left side
http://s807.photobucket.com/user/budm/library/
TV Factory reset codes listing:
http://www.badcaps.net/forum/showthread.php?t=24809Comment
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Re: how to determine if its a bad main or tcon?
If all the voltages are good and there is nothing else obviously wrong the only way I know of is to use a scope to check the LVDS signals like CapLeaker saysPlease do not PM me with questions! Questions via PM will not be answered. Post on the forums instead!
For service manual, schematic, boardview (board view), datasheet, cad - use our search.Comment
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Hi,
i want to repair a Sony KD-75XF9005 TV that initially only showed a grey picture.
Backlight seems to work, Sound (Setup menu after reset) works.
If i dissconnect the left FFC cable from TCON to panel i have half a screen on the right. If left cable is connected always only the grey screen.
Interchanged the cables, its always only the right side that is working. Always grey if left side is connected.
With my small knowledge i would think at least the cables are good.
Can this happen because of a bad tcon board?
Or is it always a bad/shorted... -
This thread is about trying to get an Universal Main Board to work with a Sharp TCON and panel.
I have a Sharp LC-46D85UN TV that has had a main board issue. Since this model is from 2009, I am not able to find an exact replacement of the main board. Instead, I decided to see if I can future proof this tv by getting a Universal Main Board (T53U21.2) from China to work with the Sharp TCON (CPWBX4291TPZA) and panel. The universal main board supports a 8 bit dual channel LVDS interface whereas the TCON requires a 10 bit dual channel LVDS input. I have modded the LVDS connector to match... -
Hello all ~
Hope this finds you well. This LG 82UN8570AUD (April 2021 model) 4K UHD television has full audio capabilities but video is compromised / problematic.
When I picked up this large LG tv it had a full black screen upon startup. Previous owner said it just went black one day. No popping sound or anything else of note.
I got the display to work by taping off several traces of the right-hand side ribbon cable on the TCON that leads from TCON to PANEL. However, despite dozens and dozens of attempts to find the right combination / range of traces taped... -
Hello all,
I’ve tried to repair TVs in the past with some luck. Toms repair manuals got taken down and now thats a bit harder.
I picked this TV up hoping for a quick fix. When the TV would power on, only the backlights would come on. The owner told me they heard loud screeching before it shut off. This alone makes me want to think the main board has an issue.
As I researched, I found the TCON/driver boards were an issue on this unit. I went in troubleshooting the TCON but found good voltages on the TCON. I followed shop jimmys guide to test the transistors and they seem okay.... -
My Oled Tv is 55inch tv, 3 days ago I notice that middle of the screen is getting warmer and on picture I have ghosting, missing red color. Color red was still displaying, but it was not so strong as corners of the screen and watching some movies makes me angry.
Then I get an idea to take it apart and clean boards from dust.
In side of Tv was not so bad, I take compressed air in can, and gently blow up.
Also I was thinking to styrofoam sponge to isolate power board from screen that the middle of the screen will not worm so much. Because Led on screen when gets higher...
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