Sony KDL-55ex720 tab bond problem and TCON?

[curt2199]

I picked this TV up for free and the person admitted to spraying the screen with windex which then cause this problem. There were just a few lines but removing the bezel and frame caused more to pop up. I discovered that the yellow ribbon cable has separated and putting pressure on it cause almost all the lines to go away leaving what you see in the picture. I have since cleaned up all the corrosion caused by the windex. When pushing on a different yellow ribbon the large vertical bands go to one solid dark color but they never disappear so I'm wondering if the windex shorted a connection and cause the TCON to go bad as well?

[budwich]

Re: Sony KDL-55ex720 tab bond problem and TCON?

those connection ... if they are still like that, need more cleaning... severely but gently... :-)

[Davi.p]

Re: Sony KDL-55ex720 tab bond problem and TCON?

This tv needs about a magician to turn back to the early days... no damage to tcon..

[budm]

Re: Sony KDL-55ex720 tab bond problem and TCON?

You need good magnifying glass to inspect the boding and the copper traces to see if any conductor got eaten sway or not, and yes, it needs really good cleaning.

[curt2199]

Re: Sony KDL-55ex720 tab bond problem and TCON?

Yep, I cleaned the corrosion off with a fiberglass brush. The some of the conductor got eaten away that wasn't under the yellow ribbon attached to the board. At this point the biggest issue is the yellow ribbon itself requires pressure on it to keep the lines from showing. It appears it itself has separated.

[Davi.p]

Re: Sony KDL-55ex720 tab bond problem and TCON?

I think you can do anything because if you have to press on the tab, the tab itself is damaged, so you have to jump over the corrosion on th tab, but on the tab you can't solder with tin, only with silver paint, but there are too much traces damaged..

[curt2199]

Re: Sony KDL-55ex720 tab bond problem and TCON?

Actually it's not the tab. I have to put pressure in the middle of the yellow ribbon because there is a clear separation between the two layers of the ribbon as I can see the gap. If I push the two layers together then most of the lines go away. I was trying To come up with some sort of adhesive that I could use to seal the two ribbon layers back together but wouldn't be conductive shorting the traces in the ribbon.

[curt2199]

Re: Sony KDL-55ex720 tab bond problem and TCON?

I also tried hearing the cable to see if it would self-stick back together but that didn't work.

[chrismurphy]

Re: Sony KDL-55ex720 tab bond problem and TCON?

You probably dont want to hear this but you wont be able to repair this
There are places that will rebond the tabs but at a cost of over $300 , for the age and size probably not worth it

[curt2199]

Re: Sony KDL-55ex720 tab bond problem and TCON?

Yeah I figured as much. It was free so was just hoping I could make it work. I'm not ok t anything and I'll pull the boards and put them on eBay.

[Ashg]

Re: Sony KDL-55ex720 tab bond problem and TCON?

Styrofoam to add pressure on the card.