BoardHoarder
Member
Last Activity: 08-15-2024, 03:42 PM
Joined: 10-13-2017
Location: Pittsburgh,Pennsylvania
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The thing that doesn’t make sense to me is if you can take the entire main board away and get the test pattern with backlights, there can be no signal coming from the main. Most sets that I fix are LGs with LED strip replacements or Samsungs with main board issues and I don’t see a lot of Sony to know all of their quirks but I have watched Nick’s YouTube videos. I fixed a main board issue in a 55X900F that did give me the test pattern that was slightly different than what I’m seeing on this D-series. In the 900F the main was fully out of the set and I got the test pattern with backlight.... -
I’m not sure when Sony started this but in this model and newer ones if the TCON doesn’t see video from the main board, it starts running a test pattern which basically tests the panel, backlights and power supply. Solid colors appear on the screen every few seconds and is helpful as a quick test. I know that I have more problems than just the main board because I have to still jumper standby voltage to BL ON and TCON on to get the test pattern to show up and the TV will not power the backlight. If I substitute using an LED tester to power a quadrant of the screen, I can see the test patterns...Leave a comment:
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XBR-65X850D Backlight/Power On Help
Currently trying to save a 65” 850D that definitely has a main board issue. Power supply has standby voltage and PS ON pin shows 3.5VDC but main has no signs of life…..no light under Sony logo and no optical port lit up. 12VDC is created by main board but no input triggers from main = no TCON 12V and no BL ON voltage present. I know about the trick of pulling the main to trigger the test pattern from the TCON but I get no backlight. If I jumper the 3.5VDC to TCON ON and BL ON, I can shine a light on the panel and see solid green, red, blue and white cycling. The 4 + backlight pins on the power... -
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!...Leave a 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.Leave a 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?Leave a comment:
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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 TPS65162Leave a comment:
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Re: XBR55X850B Backlight, audio but no video
Tcon...Leave a 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.Leave a comment:
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XBR55X850B Backlight, audio but no video
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 -
Re: Sharp LC-70LE757U Flashing 2-5 :-( can it be saved economically?
This is not my main TV and I paid nothing for it as I work for a custom install company and have saved many sets from the trash heap and given many TVs away to family members that were recaps/simple fixes. Ripping that tabs off did allow me to connect all 4 ribbons and get a full picture without the shutdown error and I didn't notice the dark spot until then. The spot is most noticeable when there is dark or high contrast material in that area of the screen. Pure white shows up as grey and bright colors show up...Leave a comment:
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Re: Sharp LC-70LE757U Flashing 2-5 :-( can it be saved economically?
Sorry, pic didn't make it.......Leave a comment:
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Re: Sharp LC-70LE757U Flashing 2-5 :-( can it be saved economically?
Ripped off all 8 tabs from the left edge and now have a dark spotLeave a comment:
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Re: Sharp LC-70LE757U Flashing 2-5 :-( can it be saved economically?
I was finally able to spend some time with this again and got the final bezel off. I do indeed have 8 tabs bonded to the edge of the panel. Here are the pics.......Leave a comment:
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Re: Sharp LC-70LE757U Flashing 2-5 :-( can it be saved economically?
I finally had a chance to dig this set back out from my stash and try to get the bezel off of the edge. There is an aluminum bezel in 2 pieces, one piece on the bottom that covers the driver boards and LCD panel ribbons and one piece that wraps around the left, top and right edge. This reveals only panel tabs on the bottom of the panel and nothing on the top or sides like a conventional panel. 4 ribbons from the TCON to the driver boards and half of the set will run with full color with ribbon #3...Leave a comment:
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Re: Sharp LC-70LE757U Flashing 2-5 :-( can it be saved economically?
So happy that I stumbled across this thread and would love to save an LC70UD27U 4K set that has the 2-5 blink code. I am able to get an image on screen if I unplug one of the 4 ribbons from the t con so I know which side is affected. Has anyone tried the tab removal on a 4K set yet?Leave a comment:
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