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

[budwich]

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

no problem... thanks again for your help along the way. My english ain't so good either but that's just me... :-)

Those pictures are kind of at the wrong angle giving a false impression... but the white piece of plastic was put there by me (also at the four other "fingers") to prevent them from touching the edge boards during testing. Once the bezel is put back, it goes into the "slot" and prevents the "fingers" from coming close. However, the boards are actually quite loosing mounted and move. The pads shown in the picture are supposed to help prevent the boards from touching the bezel once it is in place BUT I put a few more smaller pads in various places to ensure that the boards never move towards the bezel. I hear you about screwing back the bezel into place. If I can't get the thing back together without ending up with the defect again, then it will be "parts recycled" as I don't need another set and was just trying to save it from the recycle bin.

[budwich]

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

As Davi.p indicated, "reframing" the unit appears to cause some "faulting" again. The display is normal for about 99% of the time but goes back to "faulted" here and there. :-(
I am going to try some further shimming on the external side of the frame to some structure points with some white plastic strips that I was using during the testing to see if it helps.

[freakaftr8]

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

I noticed you are "shimming the board side of thbe ribbon. What happens if you press on the LCD side of the ribbon?

[budwich]

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

:-( not sure if I "pressured" very close to the panel bonding area. I did lightly push down on the area over top of the driver. It did have an impact but I knew that I really didn't want to put anything in that area in terms of padding.

Anyways, its back together for now (except for 2 "extra" screws...:-) ).

Here is a picture of the same display that posted earlier. There is some uniformity / brightness issue across the screen as you move to the right where the problem was, but overall, certainly a useable result. Not sure for how long though.

[budwich]

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

So this "thing" appears to be somewhat of a "hit and miss"... :-)
A large percentage of the time, the picture is stable / good but there are periods (no pattern) when the failure comes back. Touching the corner of the frame lightly appears to get it back in control. I find that strange that such small amounts "pressure" can impact the result. There is something more to the story that we may be missing about the failure.... maybe. I am thinking about possibly drilling / mounting a screw in the back panel that will protrude thru to the interior metal bezel and can be tighten to add some pressure at that point.

[vinceroger69]

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

where do you think the failure is on that bond where it joins the lcd panel or the panel pcb joint or the cof on the flex ive read threads where it has been different points on the tabs that fail on that particular set.

[budwich]

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

I looked at both ends with my glasses on and didn't see any obvious issues like heating or gaps or such. My "pressure pad" is basically sitting just above the contact points of the edge board. That area was where I readily got a "corrected picture" by lightly touching the tab. I just find it hard to believe that the amount of "pressure" when it is fully assembled is very very slight to cause a change from "fault" to "good" is doing much.... maybe I don't understand all the physical forces in play.

[budwich]

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

looking a bit closer at the picture that I posted a bit back that shows most of the tab contact area on the edge board, I am now wondering about that screw (lower left side). I wonder if its got an issue related to providing grounding to that area of the board... maybe .

[vinceroger69]

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

in budm,s link i shared pic 15 shows he put the pad over the chip on flex area hence i asked where yours seemed to of failed i know each set may fail differently though certainly a hard fault too try and fix so the set is watchable atleast.

[Davi.p]

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

The faulty area i think is almost always the same, it's not the glued part but is a very tight area where finish the pcb glued part and the ribbon lifts and begins the curve, in that area under the ribbon there's a 1mm about of tracks free from protective paint, i think that the moist and oxidation can be an answer on why it becomes interrupted, soon i'll try a new approach 'cause in the past i've failed due to uncomfortable work at my house with theese beast screens..

[budwich]

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

the set has run for over 10 hours so it doesn't appear to be any type of heat issue. Its in a cool basement which might have helped. I still don't understand with the set (fully put back together, all screws in place) sitting on a stand, displaying a picture that the picture may go into the "failure condition" and then just a very light touch of the top right corner of the set with any most no force, certainly not enough to move any thing (if you saw the stand, you would know why) and the picture "failure" corrects itself. There is no "twisting of the frame" effort or anything intrusive like that. I just can't believe that a "poor contact" can be that sensitive.

[Davi.p]

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

It's a matter of contact, already seen well and studied for hours, the broken track or tracks makes contact trhough a bridge made by the pcb gold plated pads, the distance is so tiny that with heat and dilatation a little blow / hit makes the parts to get nearer and make contact.

[budwich]

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

So, I was having "cold start up" issues such that most of the time after a long shut down, the tv would only start in the "failure mode display". I decided to tap in a #6 machine screw into the plastic back cover which goes down towards the metal bezel plating.
I can then simply tighten it to a degree to put pressure on the bezel plate which in turn transfers the force into the underlying pressure pad that I had put on the tab. In the picture you see two holes. I tried the one to the right, and was not able to get the desired result. It only caused a "flicker picture" with the dark area removed, so it was close. Anyways, I am now waiting on a "cold start moment" to see if I have actually done anything... :-)

[freakaftr8]

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

Most of the time I have found the issue not at the panel board ribbon connections but at the LCD screen section of the ribbon. I have put a shim between the metal frame and the LCD screen and tighten that ever so slightly just to achieve the result and 95% of the time it works

[budwich]

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

:-( I was probably over excited that pressure on the edge board side of things resulted in a good display for a long period of time when the set was not fully assembled.

One question remains... how successful is the "putting pressure at the panel side" in terms of longevity? few months, few days, hours?

I will probably do a disassemble and "recheck" things. I am some what worried that I may not be able to remove the pressure pad that I placed on the edge board side without damaging the contact area / tab as the glue of the "weather strip" is pretty good. Maybe just leave in place any way.

[budwich]

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

I took it back apart (easy after the first time). Freakaftr8, you were right. It appears to be more sensitive to pressure at the panel. I cut and stuck on some "reduced" weather stripping across the panel side tab area. Its not perfect (along with the previous pad on the edge board) but I don't want to chance trying to remove / move at the glue seems to be quite "set" and I am afraid that I will damage the tab bond further. Hopefully most of the pressure force will be directed to the contact area as oppose to just "offset" the "ledge" of the contacts. :-(

[budwich]

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

As Davi.p suggested, there seems to be some sensitivity when I tightened the side metal frame bezel screw associated with that corner. I will try leaving it a bit looser than the rest and hope. :-(

[Davi.p]

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

I don't understand, the screw you put have worked or not? Is not the right type of screw, needed a wood type.. i'm quite doubtful of the thing that is the panel's glued part that is detaching.. if you press the pcb part the ribbon tend to go away from screen...

[budwich]

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

The screw is a machine screw. It didn't totally fix the issue. I still had to do some "bezel twisting" to get the picture good again. I used a normal tap and tapped the thread of the plastic back so that the machine screw threads fine into the hole.

As you and Freakaftr8 pointed out, it is a connection problem. If you press on the PCB part of the ribbon, the ribbon somewhat bends up which causes a change also at the panel part. This leads one to believe that the problem is at the pcb but after more testing, I found that the panel portion was more sensitive to a pressure change. No problem, as my picture shows, I now have pads at both the pcb and panel contact areas. I still found as I am starting to re-assemble, that it remain sensitive to pressure changes depending on how assembly screws are tightened. I have not found a good solution that will always allow the set to work without some form of "physical effort". :-(
I am waiting for it to cool back down and thinking about what else might work.

[Davi.p]

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

Bah, i have examined only 2 tv with this problem, and none of the two reacted to pressure at glass level, also on many YT videos they touch only the pcb part. Over than this, this could be a good thing to know since if it was true, none of the lines that outputs from the COF can be interrupted as each line controls only a column of the screen, remains data/power lines to side drivers, them can be "jumped" by the side with wires soldered with silver paint or with luck also tin..