Trying to save a 55X850B from being scrapped but had no history of what was tried with this TV. Started off with no standby light but standby voltage present to main board and optical port would light up when plugged in, no tcon 12V or trigger and no BL ON. Bought used main on eBay and now have backlight, audio and the ability to turn set on and off from keypad and remote but zero video. 12V to tcon is good along with fuse, some DC voltages present on top side of tcon near LVDS cables but nothing on lower half but not sure what test points to use. How can I rule out bad panel or tcon? TIA
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Re: XBR55X850B Backlight, audio but no video
Test connector from mainboard to powerboard on powerboard side with all boards hooked up, test with tv plugged in but off then hit power, report both conditions here, give pin number, pin description/name and condition both off and when you hit power on. Procedure in second link below in signature if needed. meter set at 20 vdc.Quit because THIS SITE LETS A ROGUE MEMBER TYPE ANY GARBAGE HE PLEASES AND THE POWERS THAT BE NEVER DO ANYTHING ABOUT IT SO HE NEVER QUITS. THEN YOU GET A PENALTY FOR RESPONDING TO HIS ATTACKS. BEEN GOING ON FOR WAY TOO LONG. DONE SUPPORTING A SITE THAT ALLOWS THIS BS. -
Re: XBR55X850B Backlight, audio but no video
Please post good clear straight shot of the whole T-CON board. There should be lots of Voltage test points on that T-CON board and we also need to check the DC resistance on those test points also.Last edited by budm; 07-30-2019, 06:47 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: XBR55X850B Backlight, audio but no video
is the panel ok? you have backlight right? so look for obvious cracks on lcd panel. can you provide pictures for us to speed up the repair process.
Never stop LEARNING because life never stops TEACHING!Comment
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Re: XBR55X850B Backlight, audio but no video
I can see that the panel is not cracked but I am more worried about shorted components on the driver boards attached to the bottom of the panel.Comment
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Re: XBR55X850B Backlight, audio but no video
TconAttached FilesComment
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Re: XBR55X850B Backlight, audio but no video
Pictures is not clear enough for me to read all the test points.
I can see VDD_L, VDD_R, VGL_L, VGL_R, VCC33.
Look for VGL_L, VGL_R.
You get the idea what we are looking for, Vxxx.
Test them Voltages
P/n of the IC next to the inductor with 220 printed on top?.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: XBR55X850B Backlight, audio but no video
I stared at the board and found every tiny round gold point and here’s what I get:
VDD_L 16.26VDC
VDD_R 16.28VDC
VGG_L -5.44VDC
VGL_R -5.44VDC
VCC33 3.34VDC
VCC18 2.01VDC
VGH_I_R 28.8VDC
VGH_I_L 28.9VDC
The top of that square IC that is symmetrical to the other side is TPS65162Comment
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Re: XBR55X850B Backlight, audio but no video
Those Voltages look to be normal.
TPS65162 LCD BIAS IC.
https://cdn.badcaps-static.com/pdfs/...f85ec7ae25.pdfNever 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: XBR55X850B Backlight, audio but no video
Being a sony, they always recommend a firmware update after a mainboard switch, can you try it thru a flash drive?Quit because THIS SITE LETS A ROGUE MEMBER TYPE ANY GARBAGE HE PLEASES AND THE POWERS THAT BE NEVER DO ANYTHING ABOUT IT SO HE NEVER QUITS. THEN YOU GET A PENALTY FOR RESPONDING TO HIS ATTACKS. BEEN GOING ON FOR WAY TOO LONG. DONE SUPPORTING A SITE THAT ALLOWS THIS BS.Comment
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Re: XBR55X850B Backlight, audio but no video
Is it possible to not have video from the main board or do those test points confirm that it is processing video? Any way to force a test pattern sequence?Comment
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Re: XBR55X850B Backlight, audio but no video
So purely by accident I do get solid colors to display on the entire panel. I put the USB stick with the firmware on it and did the factory reset with VOL- and POWER while plugging in. The standby light turned solid blue. I was checking connections on the main board and pulled the larger of the 2 LVDS cables and the screen went solid green, then red, then white and finally black. It just repeated this sequence until I reseated the LVDS and now back to a black screen with backlight.Comment
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Re: XBR55X850B Backlight, audio but no video
Looking into the LVDS cables at the main board paid off! They didn't appear to be evenly seated and the smaller one of the two was pushed in slightly farther and the little tabs at the end of the cable were torn off from not pushing the releases on top of the main board connection. Pulled out slightly on the LVDS and now have full and perfect video. Another 4K saved from the scrap heap. Thanks all for the help!Attached FilesComment
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Re: XBR55X850B Backlight, audio but no video
Good news, sometime good inspection helps, so it may have happened when you install the replacement main board.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: XBR55X850B Backlight, audio but no video
Hi
do you have any advice how to remove a sony 65inch pannel to replace the back light strips.....Comment
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Hi There,
This TV was auto switching off after few seconds with some vertical lines on the screen, so got a new TCON board and replaced it.
After replacing the TCON board it was working fine and i set it up with everything, used for few hours, then had the bright idea to update the software on it. During the update process, TV switched off and now no audio or video. No relay switch sound.
More Details
TV Model - LG OLED77G1PUA
Got the same exact TCON board from TVPartsToday and replaced it. But didnt transfer the EPPROM data (didnt... -
The Problem: This player has a toggle switch to select between Stereo, Mono R, and Mono L. Regardless of the setting it outputs the sound to both the L&R audio jacks. In the Mono R position, the audio output level is normal (from both the L and R audio output jacks), in the Stereo position the audio output is about half the volume, and in Mono L, it's about 3/4 the volume. Something about putting it into Stereo mode is causing the volume to drop significantly and I can't figure it out.
The player processes the audio signal using two different reference frequencies. The "R"... -
I have a Vizio D32f-E1 LCD TV that does NOT have a TCON board.
This TV recently went through some 'death throes' and now won't boot. The first problem that began to manifest was while watching tv, the screen would 'freeze', and the image would dim over a few seconds until it was very dark. HOWEVER, the audio of the show would continue as normal. I could power off the TV for 5-20 seconds, power back on, and the video would be normal. This would occur 1-3 times when the TV was first started, and would not happen again after the TV was 'warmed up'. Not ideal, but this glitch was manageable.... -
this tv is throwing me for a loop. do samsung tvs no longer have the backlight self test feature built into the power supply?
i tested the backlight with my LED tester and it lights up both strips. one of them reads 100v and the other reads 63.7v.
unplugged mainboard from power supply but left backlight plugged in, and then plugged psu wall power in. expected to see backlights light up but see nothing.
according to how ive diagnosed in the past, this would almost always be a bad power supply. replacement power supply was cheap like 20$ from ebay. but still i get not even... -
Hi! This TV was ready for the trash so I picked it up before it was thrown away
It's pretty new, so I thought I should give it a try. I plugged it in at home and I was expecting blown backlight as most of the TV's that get to me, but in this case it showed backlight with no video at all (no logo no menu no nothing).
TV seems internally responsive, drives stdby led red when OFF, responds to remote to turn on and off, but gets no image at all
Anything common on these sets to start with?
Thanks!...
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