Samsung UE55B7000 issues

[graham01]

Hi everyone,

I acquired this TV because it had water damage, water got spilled down the front of the screen and it caused the whole screen to display a slow moving white image. I took the whole TV apart down to the panel and found the boards that run along the bottom of the screen had a lot of corrosion where the water had been (unfortunately irreplaceable as they are connected to the screen)

Anyway I accidentally blew the Tcon board up playing around with it so ordered a new one without any hope, and suprisingly after I cleaned up the corrosion and fitted the new Tcon, the TV sprung back to life.... almost.

Now the left hand side of the screen is a bit lighter than the right, and there are 2 evenly sized thin lines that are the brightest, one on the very right and one just offset to the middle-left. Could I possibly get lucky with this too?

The Tcon I bought was taken from a 40" TV where as this one is 55", it was the exact same model number and looks identical too.

Picture should be attached of the TV.

Many thanks,
Graham

[cmj21973]

Re: Samsung UE55B7000 issues

If you don't have the srevice manual, here is a link to it:
http://elektrotanya.com/samsung_ue40.../download.html

The SM has a section on adjustments and self test.

While the T-CON board is the same, I'm not sure if the setting are the same or not.
To me it looks like you need to make some adjusments.

Please wait for someone with more experience and knowledge to respond.

[graham01]

Re: Samsung UE55B7000 issues

Hi there, thank you for the response, how do I download that file? I tried in Firefox as it suggested and also Chrome and IE, I cant find a download link?

Regards

[graham01]

Re: Samsung UE55B7000 issues

Forget that, managed to download it, thanks!

[graham01]

Re: Samsung UE55B7000 issues

Hello everyone, I hope I can revive this topic and someone with knowledge and skill can help me out with the repair..

It turns out that corrosion has damaged some of the pins on the panel's ribbon's and obviously these are irreplaceable, so I thought I might as well have a go at repairing it.

The last picture shows the pins that are damaged, some pins don't connect to anything, 5 pins connect to the surface mounted capacitors (2 of them connect to the same capacitor) and 2 pins seem to transfer through the board, although on the other side of the board they don't appear to connect to anything, and I am fairly confident they don't do anything.

So, my plan was to carefully scratch off the ribbon above the pins, solder some very thin copper wires on top, and connect them to the corresponding capacitors. It took me all day and I was extremely careful, I had to do it using a USB microscope since they are so small I could hardly see what I was doing.. The first picture shows my repair attempt, and I am fairly confident I fixed all the connections that I know *do something*

Annoyingly I plugged it all back in and it achieved nothing. The ribbon I started with is the one on the very right of the screen, and as you can see in the original picture in my first post, this strip is much brighter than the rest of the screen.

I am confused. Its like all the pixels are getting the correct information as they display fine, its just like the intensity is missing?!

I would like to know peoples opinion on the 2 pins that transfer through the board but are not connected to anything on the other side, could there be rails sandwiched inside the board? I have taken a snapshot of the side of the board and to me it really looks like there is nothing..

[tom66]

Re: Samsung UE55B7000 issues

LCDs use several voltages to drive the display pixels properly. Check the voltages at AP1ON,AP1ED etc. on all columns are nearly the same.

[graham01]

Re: Samsung UE55B7000 issues

Hi Tom, did that, they all seem pretty close, give or take a few thou of a volt!

[uberplasma]

Re: Samsung UE55B7000 issues

a pic of the other side of the board might help but if you don't see anything but an pass through there is probably a layer between, do the bright light trick to see it or test some points for continuity on the board side on the connectors you didn't re-establish contact, they may be needed.

[graham01]

Re: Samsung UE55B7000 issues

hello, i did the bright light trick and i can safely say those contacts do nothing, the massive worry that just dawned on me now though is that the rails on the actual ribbons are only just a print on the surface, so scratching away the ribbon plastic also removes the rails is that right?

[tom66]

Re: Samsung UE55B7000 issues

There are also driver ICs on each flex connector... these can go bad and sadly are unreplaceable. You have hit upon a major issue with consumer electronics, they are not designed to be repaired, otherwise those connectors would be removable and the chips would ideally be on the driver board.

[graham01]

Re: Samsung UE55B7000 issues

yea, I've given up, going to accept the loss

[tom66]

Re: Samsung UE55B7000 issues

yea, I've given up, going to accept the loss

If you don't mind me asking how much did you pay for it?

[graham01]

Re: Samsung UE55B7000 issues

about £250, then the new Tcon was about £100 in total..

[tom66]

Re: Samsung UE55B7000 issues

about £250, then the new Tcon was about £100 in total..

That sucks . I wish you luck on another repair.

[graham01]

Re: Samsung UE55B7000 issues

thanks for all your help anyway!

[bbjunkie]

Re: Samsung UE55B7000 issues

Owch! that's a big loss. I got stung recently on a small samsung that had bad backlight, turned out the CCFLs weren't replaceable and it needs a panel. Nowhere near the same loss you have run into though.

Best of luck with your next couple, don't let it put you off. It's a bit like the stock market - never invest more than you are willing to loose

[graham01]

Re: Samsung UE55B7000 issues

thanks, I'm just gonna flog it on ebay for 99p and state what I have done and that it will most likely need a new panel, I imagine someone probably has a panel that will fit it so I might still get a bit of money for it, or someone might even be able to revive it with better equipment than a £10 soldering iron!

[graham01]

Re: Samsung UE55B7000 issues

Okay! I discovered yesterday that I was able to do what I wanted to, even though I thought it would be impossible.. i.e. scratching off the top of the ribbons on single pins and manage to solder just to one without creating a short circuit, I didn't think I would even be able to achieve this, but after discovering that the tracks on the ribbons are only a print, and scratching off the plastic also removed the track, ruining it even more..

BUT! I only did this to one ribbon, there are 3 more that need repairing, and I think I can scratch off just the bottom half of the pin, so I can solder to the tab on the board, and another half of the track on the ribbon is still in contact.. So I think I am safe for the other 3 ribbons..

I need peoples opinions here, since the ribbon tracks are only a print, are they exposed on the underside? I am thinking maybe I can attach a really thin copper thread to the tracks on the ribbon I experimented with yesterday, maybe with some hot glue or something? I have a very good USB microscope which I used yesterday, and quite a steady hand..

[tom66]

Re: Samsung UE55B7000 issues

Okay! I discovered yesterday that I was able to do what I wanted to, even though I thought it would be impossible.. i.e. scratching off the top of the ribbons on single pins and manage to solder just to one without creating a short circuit, I didn't think I would even be able to achieve this, but after discovering that the tracks on the ribbons are only a print, and scratching off the plastic also removed the track, ruining it even more..

BUT! I only did this to one ribbon, there are 3 more that need repairing, and I think I can scratch off just the bottom half of the pin, so I can solder to the tab on the board, and another half of the track on the ribbon is still in contact.. So I think I am safe for the other 3 ribbons..

I need peoples opinions here, since the ribbon tracks are only a print, are they exposed on the underside? I am thinking maybe I can attach a really thin copper thread to the tracks on the ribbon I experimented with yesterday, maybe with some hot glue or something? I have a very good USB microscope which I used yesterday, and quite a steady hand..

They are known as flat flex cables. They are technically a form of flexible printed circuit board. The top surface is probably plastic, but could be a form of flexible fiberglass. It's probably the same on both sides. The inner layer is copper, but extremely thin.

[graham01]

Re: Samsung UE55B7000 issues

Yea, I was looking at the tracks at 200x, there is even holes and cracks in them, that's why I thought they were only some kind of print