Toshiba 50L7363D image issues (t-con?)

[MeAndTheBoys]

Hi folks,
I have a Toshiba 50L7363D on my workbench wich has image issues.
I´ve not opened it so far (will do so tomorrow)
Do you have a hint where I can start troubleshooting?

I suspect t-con board?

I have the equipment (at work) to replace smd chips and even BGA´s, so I`m aiming to avoid replacing whole (expensive) bords.

Thanks in advance!
Ben

[MeAndTheBoys]

Re: Toshiba 50L7363D image issues (t-con?)

Hi folks,
I have a Toshiba 50L7363D on my workbench wich has image issues.
I´ve not opened it so far (will do so tomorrow)
Do you have a hint where I can start troubleshooting?

I suspect t-con board?

I have the equipment (at work) to replace smd chips and even BGA´s, so I`m aiming to avoid replacing whole (expensive) bords.

Thanks in advance!
Ben

Update:
Reseated all ribbon cables, no improvement.
T-con is a CHIMEI INNOLUX V420HK1-CS5

Can anybody help me out with a clue? :-)

[yokoono]

Re: Toshiba 50L7363D image issues (t-con?)

Check for starters that there are no backlight issues.

[nomoresonys]

Re: Toshiba 50L7363D image issues (t-con?)

One possibility: https://www.youtube.com/watch?v=H4sro4FMq18

[MeAndTheBoys]

Re: Toshiba 50L7363D image issues (t-con?)

Check for starters that there are no backlight issues.

i checked that. I also have this wierd double Image, wich I suspect has nothing to do with backlight. The light is nice and even through the whole picture.

[MeAndTheBoys]

Re: Toshiba 50L7363D image issues (t-con?)

One possibility: https://www.youtube.com/watch?v=H4sro4FMq18

Thanks, will check that tomorrow!

[yokoono]

Re: Toshiba 50L7363D image issues (t-con?)

i checked that. I also have this wierd double Image, wich I suspect has nothing to do with backlight. The light is nice and even through the whole picture.

I thought this is the original image, not the double image. Hard to say. 50% t-con, 50% panel. Because it is cheaper the ideal would be to have a defective t-con.

[nomoresonys]

Re: Toshiba 50L7363D image issues (t-con?)

Maybe try the "cut tape" method: https://www.youtube.com/watch?v=j7vl7-vZEL8

[MeAndTheBoys]

Re: Toshiba 50L7363D image issues (t-con?)

tried cut tape - didnt work - wierd thing is when I disconnect the right side of the t.con the left side of the image becomes clear !

[MeAndTheBoys]

Re: Toshiba 50L7363D image issues (t-con?)

Replaced tcon, same issue....

[vinceroger69]

Re: Toshiba 50L7363D image issues (t-con?)

any damage/burnt parts on the lcd panel pcb

[MeAndTheBoys]

Re: Toshiba 50L7363D image issues (t-con?)

any damage/burnt parts on the lcd panel pcb

By LCD panel PCB you mean the ones that are recieving data from the T-Con?
I found no burnt parts on any pcb...

[vinceroger69]

Re: Toshiba 50L7363D image issues (t-con?)

there is a pcb thats bonded to the lcd panel sometimes we see damage on this pcb liquid shorted smd caps etc

[MeAndTheBoys]

Re: Toshiba 50L7363D image issues (t-con?)

there is a pcb thats bonded to the lcd panel sometimes we see damage on this pcb liquid shorted smd caps etc

found no blown smd caps or liquid damage.
BUT
If i tape the 3 right contacts of the ribbon cable of the "bad" side of the panel I get a halfway decent image (see attachment)
One side of the image is still darker and slowly fades when changing the menu for example...

do you guys have any more tips? I´m ready to give up on this one...

[diif]

Re: Toshiba 50L7363D image issues (t-con?)

The smd caps won't look blow, have you tested for a short ?

[MeAndTheBoys]

Re: Toshiba 50L7363D image issues (t-con?)

The smd caps won't look blow, have you tested for a short ?

just checked the caps on the lcd panel pcb. -> no shorts

[neilc6]

Re: Toshiba 50L7363D image issues (t-con?)

Bad panel. Last resort is to rip off the side tabs on the bad side.

[budwich]

Re: Toshiba 50L7363D image issues (t-con?)

found no blown smd caps or liquid damage.
BUT
If i tape the 3 right contacts of the ribbon cable of the "bad" side of the panel I get a halfway decent image (see attachment)
One side of the image is still darker and slowly fades when changing the menu for example...

do you guys have any more tips? I´m ready to give up on this one...

The "tape mask off" method usually doesn't resolve issues on a panel that has side tabs IF the problem is with one of the side tab drivers. This is because the driver is still in the drive circuit for the panel and causing an issue which you are seeing. As suggested, the last resort is to removed the tabs from the "bad side". The result will likely be a good picture. This is assuming that the problem isn't with the bottom driver board on that side... such as a bad smd capacitor or connection to the panel in the bottom corner which is used to connect signals to the side tabs (ie. thru the panel edge).

Based on my limited experience with a 46in sony, you will likely be successful with the tab removal (the sony had an issue with connection in the corner).

[yokoono]

Re: Toshiba 50L7363D image issues (t-con?)

High resistance on VGH, VGL paths between t-con and side drivers.

[nomoresonys]

Re: Toshiba 50L7363D image issues (t-con?)

Well take it down to see the side tabs and look for damage or black or burnt looking cof (chip on film) etc. also see if any get hotter than the others, lots of times the problem is obvious once you get to the side tabs.