Sony KDL46XBR4.... a new "learning journey"

[budwich]

Re: Sony KDL46XBR4.... a new "learning journey"

So with a cold start (after sitting for 1plus hours), the picture is usually flickering / dark. I decided to add a small "c" clamp (1 inch). If I tighten the clamp a bit, the picture goes normal. Turn the tv off and wait for more than 1 hour, turn it on again, the picture is again bad. Tightening doesn't really help and might be dangerous. BUT loosening a bit, allows the picture back to normal. It appears that once the pressure is in place, some form of change, either more pressure or less is enough for the tv to go to normal. The clamp is positioned almost in the same place as the holes that I put for a "tightening screw" (as pictured earlier). I am going to try putting the screw back in. It will allow me to readily either tighten or loosen just a bit to give the physical change that seems to be needed for the set to work normally. Not the best but better then "twisting" the frame all the time.

[budwich]

Re: Sony KDL46XBR4.... a new "learning journey"

its certainly tough working for your "free xmas presents"... :-)

Anyways, I took things apart once more. One to check to ensure that the edge board "ground" in and around the right side was being made consistently to the main body of the cabinet (just a simple resistance check). It was and there wasn't any change with pressuring that area.

Next, I played with the tab area in question plus moved along the panel edge in both direction including up the side using a pencil with an eraser end. The only area that was impacted was indeed the left side of the tab in question. Looking closer and trying to figure out why changes in pressure on the frame were so unpredictable as to whether they would result in a display change from good to bad or bad to good, I realized that the plastic frame component in the corner of the panel has a raised edge (about 3/32th of inch) such that the maximum the metal bezel could squeeze down on the pressure padding was limited by this "interference" of plastic. See the arrow in the picture. Thus I raised the pressure pad material thickness by adding some addition padding just to that left side of the tab area. I put back the metal bezel (tighten down screws), and things look better. I need to wait for things to cool back down to see if it holds it desired effect. Fingers are crossed.... hopefully its not memory foam ... :-)

[budwich]

Re: Sony KDL46XBR4.... a new "learning journey"

Put everything back together including the two extra screws that were "left over" from earlier attempts. It would appear that I might have succeeded in getting the thing to start up with a good display and stay that way. I will do a couple more "cold start test" just to be sure. I want to wall mount it so I am hoping it will be more "good times" than "bad times". I added weather stripping along the entire side of interest... its between the metal frame bezel and the overall plastic outer bezel.... just inside the leading edge towards the screen. I found during the earlier testing with the entire bezel mounted / in place that I could readily cause the picture to go bad / dark by pushing the side area. Hence the decision to try for some "isolation" padding.

[budwich]

Re: Sony KDL46XBR4.... a new "learning journey"

Tried some more "cold starts"... not as successful in that the picture sometimes is in "fault mode" (ie. dark side and horizontal lines) but the set seems to "fix" itself without any intervention or physical forces. It would appear that the connection point that is in trouble "burns thru" what ever the issue is and starts to run fine.

My question is... is this going to get worse... will that point / area eventually "burn up" from the repeated "spark over action"?

[Davi.p]

Re: Sony KDL46XBR4.... a new "learning journey"

Are you able to determine which line/lines are interrupted by pressing the ribbon with a toothpick especially in the right near glued part? If the lines are for example 3 and are all consecutives there's the possibility that actually the center one is the only one broken, and if that doesnt enters the COF and goes to the vertical tabs passign through the glass tracks you can jump the broken track with a wire..

[budwich]

Re: Sony KDL46XBR4.... a new "learning journey"

could be tough to do but I understand what you are saying. Its certainly more on the first set of tracks closest to the left side of the bond. If you look at the last picture that I posted, it shows how the buildup pressure pad is pressing on that side. You can almost see that the pad is on an area that appears to a "large track" that doesn't go to the COF chip.... perhaps some form of ground line(s)... maybe.

IF I look back at one of the early pictures that I posted, the lines labeled at that end have a "V1" label.... what ever that means.

[Davi.p]

Re: Sony KDL46XBR4.... a new "learning journey"

Yes is tough, if you want you can search for a correspondence between that V1 or other testpoints and the testpoints placed on the back of the side tabs, it's really uncomfortable to test there, also testpoints can have to be scratched on the green paint, be very light as it easy to scratch and also tracks under can be damaged. How much voltage is V1? I have at home a giant 60" first era LED tv by Sony with the same sympthom, i would like to investigate on it but it's really so heavy that i'm wondering if i had to sell it or investigate first on another tv with tab issue (that i have)..

[budwich]

Re: Sony KDL46XBR4.... a new "learning journey"

The display has gotten more difficult again this morning. Lots of "physical disturbance" doesn't seem to get it back to normal... :-( I guess I need to take it back apart and see what I can improve and check the suggestion by davi.p to see if it is readily possible to provide some form of alternate path.

[budwich]

Re: Sony KDL46XBR4.... a new "learning journey"

OK.... I got one for the forum... freakaftr8, budm maybe and others.
So the fault looks the same as in the sharp side tab failure where either the driver burns out or a tab bond gives out. My question is... as opposed to trying to get the tab bond at the bottom right to make "solid connection" to allow the side tabs to work correctly, how about if I just remove the side tab bonds like in the sharp "save" such that those "under powered / no power sometimes" tabs are gone and no longer impacting the picture. Will the sony then work like a "saved sharp" with the tabs on the other side functioning correctly???? What say you all?

[Davi.p]

Re: Sony KDL46XBR4.... a new "learning journey"

Bad idea....

[budwich]

Re: Sony KDL46XBR4.... a new "learning journey"

? why are you saying this... experience, design knowledge with this set?

[Davi.p]

Re: Sony KDL46XBR4.... a new "learning journey"

beause i have tear off the tabs on another screen, by desperation, but was a shame 'cause i had no good result, if one dont know how to do is a waste of chance to repair, you can follow my directions and maybe find a full recovery, the method you say is know as a non long term repair. The ripping of the tabs can also be simulated by simple flat cable masking on tcon.

[budwich]

Re: Sony KDL46XBR4.... a new "learning journey"

BUT... I think the "masking of the flat cable at the tcon" method only works IF there are no side tabs / drivers. If those drivers are not removed and left unpowered, then they load down the opposite side drivers resulting in picture issues similar to what I have posted. Further, I suspect that if the set is run with this kind of condition, then the side drivers that are OK will quickly get in trouble as they are driving horizontal lines that have "unpowered drivers" connected on the opposite side.

Note: I am not asking about removing the bottom tabs of the panel, just the ones on the side that are not getting proper powering because the bottom tab bond has no integrity.

[Davi.p]

Re: Sony KDL46XBR4.... a new "learning journey"

You're wrong, side drivers are all good so doesn't load down anything.. it's the same thing as when you disconnect half of the tcon<>panel ribbons, you get an half perfect screen, if you mask some traces like Vstrt or clock so maybe the side drivers doesn't work and works the ones on the other side, never tried...

[budwich]

Re: Sony KDL46XBR4.... a new "learning journey"

I don't think you can make that statement. If I recall correctly, disconnecting at the tcon causes a white section on that side and depending on what the failure is on the side (ie. driver shorted, driver open, poor connection, etc), the remaining connected side produces a reasonably normal picture.

The display that I see on this set when it is failure is very much like the display of a sharp with the corner cable of the panel disconnected on a bad side panel driver / tab bond. The difference is that with one driver / tab bond bad, the resulting display is less "faulty" compared to this display because on this display all the tabs / drivers are not being driven because of the bad bottom tab bond connection. This results in multiple horizontal lines along with the dark section.

what was the make / model of the panel that you tried removing the side tabs from and resulted in failure of operation?

here is picture from a person who had side tab driver issues with a sharp. In this picture, the tcon is disconnected. Note the remaining side's picture is still basically good.
https://imgur.com/eSKg2gl

Here is a recent video of sony 40 inch where the guy did try to fix the voltage to the tabs (as you suggested) but in the end just remove the tabs to get success.
https://www.youtube.com/watch?v=ZJwu7cwrttk

This give me great hope. Further, on a totally working set, one should be able to remove tabs on one side and the result should be that the TV continues to work "properly".

[Davi.p]

Re: Sony KDL46XBR4.... a new "learning journey"

It's not important my panel, it had one different issue, in the picture of the sharp the tcon is not disconnected 'cause we see a video, the video linked makes me headache, sorry not clear what he do, the starting problem is different than yours and is a known problem solvable with the removing of the side tabs, it is not a fault related to bad contact as there a pressure doesn't make difference. I repeat, not me but also other users says that removing tabs can result in a not long lasting repair. I've said all for now..

[budwich]

Re: Sony KDL46XBR4.... a new "learning journey"

the picture linked is with the tcon disconnected. You get that kind of display (instead of all white) when there are other issues on the disconnected side.

As for the video, he has a problem with side tabs that are not operating correctly and as a result, it gives a picture as shown. He takes the panel apart and checks for voltages at the side tabs just as you suggested. In his case, no voltage at the right side, voltage at the left side. He then tries to make voltage for the right side (not shown in video, just text message). He then removes the side tabs on the right and the display is good again. This appears to be the same issue as sharps with side tabs.

As for how long the panel will last with side tabs removed, don't know. So far on this forum, I have only come across 3-4 posts of people who have removed the side tabs and had the tv fail shortly there after. Right now, I have found nobody that gives an idea of a long term success using pressure on the tab bond area so I am not sure there is a good answer either way. The tv is not useable in its current form as the display fault can show up at any time. :-(

Thanks for your comments though as I wouldn't have search further trying to find other possible options. You are certainly more experienced in these areas as I personally have only seen 3 TV's in need of repair in front of me. All have been a success in one form or another. This set will be my 4th effort at trying to save from the recycle bin.

[Davi.p]

Re: Sony KDL46XBR4.... a new "learning journey"

"the picture linked is with the tcon disconnected" you mean half disconnected... please be clear.. you don't get anything other than a white screen if that side is disconnected, you're wrong.
About the video i mean that it is not showed where he tests, for what can i know he is possibly wrong at testing, seeing the garbage that it is around there he can have also confusion in the head.

[budwich]

Re: Sony KDL46XBR4.... a new "learning journey"

well I threw in the "proverbial towel". After trying alot of different pressure pad "techniques", I couldn't get the tv to respond predictably once it was all put together... :-( I am tired of disassembling / assembling (8 times in total).

The "remove the side tabs operation" was uneventful compared to sets with side edge boards. On this set where there are only side tabs, and all other circuitry is with in the the panel, removing the tabs is very very easy.

Anyways, a working tv in the hand is better than two in the "fringe"... :-)

The learning experience just re-enforced some of the things that I learned previously dealing with the 70 in sharp. :-)

[Davi.p]

Re: Sony KDL46XBR4.... a new "learning journey"

I don't understand.. you've tried to remove the tabs and the defect is still present? It's equal to before?
So you don't have tried my method?