Sony Bravia XBR4 - Negative Picture problem

It seems that LCD drive (pixel driver) board does not provide contrast control - it "pushes" to max. the drive “bias” voltage that polarises LCD crystals. These crystals then allow all available backlight to pass thru.

I would clean all ribbon cable contacts first between pixel driver board and LCD screen. If still the same... replacing the PCB may solve the problem

Pixel driver boards can be found on e-bay for next-to-nothing (around $100)…

Boky

They are not generic. And if that don't fix it, you may need to replace the whole panel and/or the "main" board.

The pixel driver board is located in the middle (at the back) very close to the bottom edge, and is connected to LCD panel (usually) via two wide, flat ribbon cables. The part number is clearly written on the PCB.

Do not remove the back cover if you don't know how to deal with lethal high voltages!!!!!

You've been warned!!!!

However, if you have sufficient experience, replacing this board can be done really quickly at a very low cost....

Otherwise, leave it to service guys….

Boky

Bottom edge? Every LCD I've seen has the Tcon board on the TOP edge.

.if you turn the panel upside down to make it easier to work on?

Boky

Ya, I prefer to stand on my head when working on Tv's, gets the blood flowing to the brain

did u try unplugging cable/dish first

Leave it unplugged from the wall mains outlet socket for couple of days and you should be okay. The sheer fact you asked the question (above) is telling me you should probably leave repair to service technician but I may be wrong(?)

Boky

Normally called TCON board. But Sony calls it the UB1 board (at least on kdl52xbr4):
$155 rebuilt
$390 new

Hi. I have a KDL-52XBR4 which shows a white screen (washed out image with streaks following any text) on the entire LCD when it is powered up. The entire screen is white and pictures in the background are visible as if you were looking at a negative. The sound is intact. It is the same problem as the Original Poster.

Removed power cord for more then a minute - plug back in - no good.

This is happening on all the HDMI, and component inputs.

I unfortunately didn't buy the extended warranty from Circuit City when I bought the TV in Jan 2008.

Can someone suggest where I can find the service manual for this TV ?

Below are the picture that shows the exact symptoms - that are uploaded by some one else who had the exact same problem on his 52XBR4 and his problem started just a month before mine.

http://www.avsforum.com/avs-vb/attac...5&d=1262935361

http://www.avsforum.com/avs-vb/attac...6&d=1262935361

Called e-support - did basic reset of TV and unplugging of power cord to see the results - still no good. Also I was suggested to call the local sony technician to have a look at it and get the report break down and call back with that report. Per the tech he said this is video module issue and he is not sure whether the video module is available separately or part of a panel. He will let me know today after finding that out by calling sony engineers. He did pretty much nothing but went through different menu options and within 2 mins said that it could be video module issue. I have to pay him 95 bucks for his 2 mins visit at my place.

Any suggestions or can I do further diagnostics by myself? Any ideas or clues are welcome.

Thank you
Vikas Patel.

The UB1 board is the frame doubling circuit. It has nothing to do with the TCON board which is a different circuit. What I see in the photo at the beginning of this post is a problem with the FB board.

http://esupport.sony.com/US/perl/new...&mdl=KDL46XBR4

And 52XBR 4/5 series are under warranty now.

Display Veteran - are you suggesting after looking at the photo at the beginning of this post (original poster) - that the problem is with UB1 board (meaning issue with frame doubling circuit)?

corrado85 - 52XBR 4/5 series are under warranty that has different issue and that too for 18 months from the purchase date. See link below that has differnet issue (lines stays on panel after turning the TV OFF).
http://esupport.sony.com/US/perl/new...R4&news_id=276
Or did I miss interpret your suggestion?

Quick Update - Sony Service repair tech came to my house - looked at the TV menus to find out some thing where he can do test - didn't find what he was looking for.

Stayed for just 5 mins hardly - and played with the menu all the time - said that he will have to check with sony engineers and will call me and update me with potential issue and it's solution.

Called Tech next day afternoon - and this is what he has to say -

70% chances - UB1 board is faulty and needs replacement - charges breakdown -
PARTS - 225.00
LABOR - 450.00
TAX - 47.25

Total 722.25.

If that does not help - then it could be the TCON board which is part of a panel - part itself would cost 3000.00 plus labor.

Faxed the breakdown to sony - waiting for their call with potential options.

Can some one please confirm that it is UB1 board that is causing this issue?
Can I replace the UB1 board by myself? Where can I find the intruction to replace the UB1 board?

Any help is highly appreciated.

Thank you

All that happens on the UB1 board is taking the 60HZ video from the FB1 and doubling it to 120HZ for the TCON board. The UB1 board has been rather robust on this model and the few failures I have seen showed up as no video or a bunch of jumbled vertical lines.

The picture at the beginning of this post involves a problem with the entire screen. All video processing on the FB1 board is performed on a frame-by-frame basis at 10-bit RGB processing. It is remotely possible for this to happen on the UB1 board but I would go for the FB1 first.

display Veteran - thanks for the update - I appreciate it. Can you tell what part number will be needed and where should I buy it from? Also can I replace the FB1 board by myself? How intensive and what kind of expertise will be required?

Thanks again.

display veteran - could you suggest which part number should we go for in this case please? There are multiple part numbers listed in the web site below -

http://www.shopjimmy.com/catalogsear...1+board+52XBR4

Thank you

I suppose if you are reasonably mechanically inclined you can do this. All of the connectors have locking devices so make sure you release them. If you pull hard and the connector does not release easily you have not disengaged the lock. Be particularly careful with the LVDS cable connector.

It is very important that you order the correct FB1 board since there were 2 different LCD panels used during the production run and each requires its own software loaded on the board. If you are not sure, post the serial number of your set and I will give the correct part number.

Serial # 8147488
Model # KDL52XBR4
PD # Dec 2007

Thanks for your time & input.

A-1362-640-A. You have an earlier version that used the G7 panel. Good luck!

display veteran
Could you also help me in identifying the correct part # for my XBR4 as well ?
I have the exact same problem of "white negative screen" as identified in this post.

Model # KDL52XBR4
Serial # 800xxxx

Can you share with us the mechanism that you use to determine the accurate part #, if I need to replace additional parts ?

Thank You in advance !!

display veteran

Per this link - http://docs.google.com/viewer?a=v&q=...Aa74rBO9ymm3_Q

This is for Model # 52XBR4
Serial Range -------- LCD Panel Type, PN & Description ----- FB Board PN
8000001 to 8099999 G7 1-802-490-12 (52" FHD HFR) A-1362-640-A FB1 BOARD, Complete
8100001 to 8499999 G8 1-802-490-31 (52" FHD HFR) A-1418-997-A FB1 BOARD, Complete

So did you misread it or I am looking at the wrong document?

Please advice - thanks again for taking the time and helping us here display veteran - we appreciate it.

My bad. I've been seeing so many threads on the 46XBR4 here that I quoted the FB1 board for this size. You are correct in that yours requires the A1418997A. Your serial numer range used the G8 panel.

bsdhaliwal: You have a very early build of this television with a G7 panel. Your FB1 part number is A1362640A. The other boards in the television are not unique to the panel type since they don't contain software.

networm and bsd.. check your inbox.. i may be able to help!

Hi Display Veteran & BSdhaliwal, I have updates for you.

The local sony tech replaced UB1 board (per tech that is what is causing this issue) - and that didn't solve my issue. I have to go for it per Sony Customer Relation team. By the way the Sony Repair Tech was now 100% positive about issue is with the PANEL.

As you have mentioned earlier it is not UB1 board that is causing this issue - you were right about it.

You said that replacing the FB1 board will solve my issue - and I asked earlier what is the right part number for my TV and you said that - I should buy A1418997A part number.

I google the part number (A1418997A) and I came across following web site and I have question in reference to that.

http://www.shopjimmy.com/catalog/pro...6-a-fb1-board/

The above site has the FB1 board part number which is slightly different then what you have recommended. So my question to you is - what is difference between -

A-1418-996-A (per ShopJimmy.com) recommend part number for Serial Number Range for KDL-52XBR4 and KDL-52XBR5 is: 8100001-8499999 and 8600001-above. And my TV does fall under this serial number range. By the way I could not find the part number that you have recommend on the same web site.

A-1418-997-A is the part number that you recommended in earlier post.

So do you see any difference between these part numbers?
Should I just go ahead and buy the part number per above website?
What are the chances that I might have issue with PANEL?

Also if some one can suggest instructions of replacing the FB1 board - would be a great help.

I would appreciate your suggestions.

Thank you.