Toshiba 26AV733G, vertical color lines, panel ChiMei V260B3-L04

[Chungalin]

This 26" TV show equidistant vertical abnormal lines. These are not solid pixel lines, but its intensity varies depending on image content. The pattern is as follows:

1 red abnormal subpixel, 4 normal pixels, 1 green abnormal subpixel, 4 normal pixels, 1 blue abnormal subpixel, 5 normal pixels. Repeat.

Panel is a ChiMei V260B3-L04.

I've checked and reseated LVDS cable, no changes.

This looks like a panel failure, doesn't it? No detachable T-CON in this case.

[Andrew F. Ali]

Re: Toshiba 26AV733G, vertical color lines, panel ChiMei V260B3-L04

This looks like a Main Board issue to me....or it could also be a bad LVDS cable....I would however tend towards the Main Board.

[Chungalin]

Re: Toshiba 26AV733G, vertical color lines, panel ChiMei V260B3-L04

Thanks for your comment. I have record of another 26AV733G repair, 4 years ago. It was the LVDS cable, but the symptom was different, it had posterized colors. I’ll check it more carefully, since it’ll be difficult to find a replacement now.

[ReeceyBurger123]

Re: Toshiba 26AV733G, vertical color lines, panel ChiMei V260B3-L04

Seems to me like panel tab bond issue which is very common for this panel. Remove the panel frame and press on the tab bonds see if it has any effect.

[Chungalin]

Re: Toshiba 26AV733G, vertical color lines, panel ChiMei V260B3-L04

I’ve been able to try another MAIN board and the issue is still there. So it’s LVDS cable or panel. I don’t think it’s cable because after checking panel datasheet, I can’t see how can a bad wire produce this effect.

If I have time I’ll try to check tab bonds and report back.

[ReeceyBurger123]

Re: Toshiba 26AV733G, vertical color lines, panel ChiMei V260B3-L04

Keep us updated.

[Chungalin]

Re: Toshiba 26AV733G, vertical color lines, panel ChiMei V260B3-L04

No luck. I’ve touched all 6 tab bonds and no changes. I’ve heated all ICs (not too many), no changes. I’m gonna give up with this one, as it’s clearly a driver failure and this one doesn’t have detachable T-CON.

The effect matches the first picture from page 43, Sony T-CON troubleshooting manual, "MULTIPLE EVENLY SPACED [vertical] LINES NOT AFFECTED BY PICTURE ZOOMING".

[ReeceyBurger123]

Re: Toshiba 26AV733G, vertical color lines, panel ChiMei V260B3-L04

Hmm have you an image of the Tcon buddy ? It could be the flat flex wires that are bonded to it and the panel.

[Chungalin]

Re: Toshiba 26AV733G, vertical color lines, panel ChiMei V260B3-L04

It could be the flat flex wires that are bonded to it and the panel.

That's what we call Tab Bonds and that's what I've touched looking for changes in lines, to no avail. Its "T-CON" is a long PCB on top side of panel. One LVDS connector at one side and 6 tab bonds to the LCD glass. A CM2652A controller IC, a Texas TPS65161 and 3-4 smaller ICs.

I've already reassembled and closed it.

[Diah]

Re: Toshiba 26AV733G, vertical color lines, panel ChiMei V260B3-L04

i got same effect on cheap LCD Chinese projector, the line cover all screen while picture color displaying correct, only deferent the lines was in double and same distances as yours, i just put the the LCD under the magnifier and on it taps there are many SMT caps, i just did heating with my soldering iron the caps pins from both side. result the picture back normal with out lines at all.

[Jane]

Re: Toshiba 26AV733G, vertical color lines, panel ChiMei V260B3-L04

@Diah: Do you mean you heated up SMT caps on the flat cable comming to LCD panel?

[Diah]

Re: Toshiba 26AV733G, vertical color lines, panel ChiMei V260B3-L04

the LCD i mentioned above are mini one, the ribbon cable which come from MB plug go direct to LCD , before the LCD on this ribbon was one Diode and about 16 SMT caps which i heat the pins of them with my soldering Iron,