Xbr55x930d. Has backlight and sound but no picture

[dooby91]

I've got an xbr55930d. It currently has backlight,sound from menus, but no picture. Replaced the main board, DPS/frame rate conversion board, and also tried a new T-con. After further testing the T-con to panel isn't getting voltage. Avdd is at 0v. Jumped twelve volts to avdd and got the panel to react and display verticle grey lines. I'm not sure how to test the boards on the panel and repair them.

https://www.badcaps.net/forum/showth...highlight=Avdd
I think the same thing is happening with this T-con described in the linked thread. The T-con is shutting down due to a failed component on the T-con or panel boards. I'm not ruling out panel at this point.

[dooby91]

Re: Xbr55x930d. Has backlight and sound but no picture

These are pictures of boards and back of tv. I hopewith your guys help I can get this fixed. My component level skills leave a lot to be desired. I'm hoping to learn more as I go.

Thanks guus

[budwich]

Re: Xbr55x930d. Has backlight and sound but no picture

disconnect, one at time, tcon to panel cables and see if anything changes.

[dooby91]

Re: Xbr55x930d. Has backlight and sound but no picture

I did try that. Nothing changed. I think the T-con talks to.the panel boards and shuts down when it sees.a problem. Just like described in the linked thread.

[budm]

Re: Xbr55x930d. Has backlight and sound but no picture

If I were you I would start checking the RESISTANCE of those caps on the panel board to see if any of them show low resistance in both directions.

[dooby91]

Re: Xbr55x930d. Has backlight and sound but no picture

I'll check tonight thanks

[freakaftr8]

Re: Xbr55x930d. Has backlight and sound but no picture

This sounds all too familiar, if you have half the panel connected to the tcon you should see half a picture. If the panel is completely disconnected then no sub voltages will be present on tcon. I agree with Bud you probably have a shorted MLCC capacitor above one of the ribbons on the drive boards to the panel.

What I've gathered over my experience with LCD panel failure, Samsung panels like to short in which the screen will not display anything, LG panels like you short in which the screen will display half image on the side that's not shorted due to the fact that data feeds both sides and in Samsung data feed serial from one side to the other

[linksys1127]

Re: Xbr55x930d. Has backlight and sound but no picture

If you check the Sony website of this model I believe it the one that is under a extended warranty until 2021. They will send a tech to your house and fix or replace. It's typically a mainboard issue. You may have received a defective one.

Kevin

[nomoresonys]

Re: Xbr55x930d. Has backlight and sound but no picture

If its under warranty DEFINITELY make sony fix/replace it, maybe they will try to make them more reliable if they have to replace enough of the faulty ones.

[dooby91]

Re: Xbr55x930d. Has backlight and sound but no picture

Yes the what Sony calls the DPS board is under warranty until 2021. However I haven't heard anything about about the panel. The symptoms of failed DPS or FRC board are no power on 3.3 v standby. This would cause the tv to not turn on at all. I also got this tv given to me so I have no proof of purchase. This is a really nice tv and would love to get it working again. I tested the capacitors and none of them are showing a direct short. I'm leaning towards a bad panel unless someone can give me any ideas on how to test the panel boards further. I took some pics of the ice on the boards if that helps. The first one is the T-con.

[dooby91]

Re: Xbr55x930d. Has backlight and sound but no picture

I think this is a Samsung panel. But I'm not sure. The T-con says Samsung.

[dooby91]

Re: Xbr55x930d. Has backlight and sound but no picture

I did some more digging not sure what this component is but its has a 0.1 ohms resistance both ways. How to ID this part to tell what it is supposed to be. This is with the Ribbon cables disconnected btw.