Samsung UH55H6400AKXXU Display Problem

[ODDS]

Re: Samsung UH55H6400AKXXU Display Problem

Hm, that could cause your issue. Interesting. It would be the first of a newer generation of TVs to suffer from this fault. Are you certain you're probing the right point?

I double checked them all, but when I wrote them down in order even I started to have doubts, I have ordered the other T-Con , for £20 it's worth the risk to be honest. Should be here Friday, so we will soon see.
Thanks to everyone so far and I will keep you updated on the issue.

Pete.

[ODDS]

Re: Samsung UH55H6400AKXXU Display Problem

Hi,

Just a quick update on this display problem.
Replacement T-Con arrived this morning, so I checked all the voltages before removing the old one and then replaced it, unfortunately the problem is still there. I checked the voltages with the replacement board in place and they were the same as the original.
So unless I have been unfortunate and have two boards with the same issue then the problem lies elsewhere.
Would anyone like to chip in with any suggestions as I haven't got a clue what I am looking for

Thanks.

[tibimakai]

Re: Samsung UH55H6400AKXXU Display Problem

but it was described as having a good picture

If it is from Ebay, then I would claim it as not correct description.

[ODDS]

Re: Samsung UH55H6400AKXXU Display Problem

If it is from Ebay, then I would claim it as not correct description.

It is the correct description, so I wouldn't think of doing that to be honest.
I'm not bothered about throwing £20 at it to eliminate a problem, and it is an exact match to the board I have.
What I was looking for was advice to sort the problem, not a way to get my money back from a reliable seller

Thanks.

[ODDS]

Re: Samsung UH55H6400AKXXU Display Problem

Hi,
Can't find an option to delete a message, so ignore this.

Thanks.

[tibimakai]

Re: Samsung UH55H6400AKXXU Display Problem

But what you do, if it's a panel problem?
You have a certain time frame to return something, what if you run out of it?

[mmartell]

Re: Samsung UH55H6400AKXXU Display Problem

He's saying he'll eat the 20Pounds cause it's not the sellers fault. Though if it's worth your time you could see if he'll take it back (as working) minus a restocking fee as it's no good to you anyhow.

[tom66]

Re: Samsung UH55H6400AKXXU Display Problem

Can you check the voltages on those gamma points but with the panel ribbons disconnected? Want to see if the panel night be causing this.

[freakaftr8]

Re: Samsung UH55H6400AKXXU Display Problem

Good call I always check made with the panel connected. This may change readings if there's a panel problem.

[ODDS]

Re: Samsung UH55H6400AKXXU Display Problem

Can you check the voltages on those gamma points but with the panel ribbons disconnected? Want to see if the panel night be causing this.

I'll get on to that tomorrow morning. So that would be the two connectors on the pic here. They connect to 2 smaller boards which are hidden under some black masking, which I presume has something to do with the lighting.
The annoying thing is, this problem only appears in brightly lit scenes. Tried all the usual adjustments and just can't get rid of it.

Thanks for the suggestions, really appreciate it.

Pete.

[ODDS]

Re: Samsung UH55H6400AKXXU Display Problem

Can you check the voltages on those gamma points but with the panel ribbons disconnected? Want to see if the panel night be causing this.

Hi tom,

Sorry for not getting these readings yet, just not had the time but should have them this morning.
In the meantime I have been looking through the service menu and noticed something which I think looks strange. Having said that I'm a complete novice so haven't a clue if it's right or not.

In the ADC/WB (meaning ?) Menu under MGA (meaning ?) there are a lot of figures, all the figures are in the high 400's to low 500's except for the two in the second column, which are B7_Gain and B8_Gain which are both around mid 200's as shown in the picture below.
Does this look 'normal' and would it be worth just trying to tweak them up a little to see what effect this has. I don't want to do anything that will cause even more problems so I need to find out exactly what these figures mean before I try anything.
I also found a load of Test Patterns each one displayed perfectly when viewed, no discolouration or distortion at all.

Thanks.

[tom66]

Re: Samsung UH55H6400AKXXU Display Problem

They are probably calibration settings for the panel, many LCDs have a blue tint so this could be them trying to calibrate this out. But, might be worth trying anyway, I can't see any harm provided you keep a note of the existing values.

[ODDS]

Re: Samsung UH55H6400AKXXU Display Problem

Hi tom,

Right then, I have checked all the voltages with the panel disconnected from the T-Con board by removing the two LVDS cables. I've compared them to the original readings and there is no change, all voltages match up to the previous readings.
Would the display of good test patterns not discount a faulty panel also ?
I haven't tried adjusting those figures yet in the service menu but Is there anything else I could check whilst I have the back off the set. I see a lot of test points on the main board feeding the T-Con there are a lot of test points labelled Odd_TX1, TX2 etc and Even:TX1, TX2. Would these be checked with the earth on the chassis again ?

Thanks.

[ODDS]

Re: Samsung UH55H6400AKXXU Display Problem

Well well well, after checking all the voltages I adjusted those two 'rogue' values in the service menu and guess what ..... no more yellow bits on the screen. I just wish I knew what the true values should be, I just took them both up to 500 as a trial for now, so it will just take a bit of tweaking now
In the picture below previously it would have had a load of yellow in it now we have white snow instead.
Thanks everyone that took the time to offer advice and suggestions, I guess I just got lucky having a nosey in the Service menu and spotting those values that seemed so different from the rest.

Thanks

[tom66]

Re: Samsung UH55H6400AKXXU Display Problem

Nice to hear it's fixed. Did you see if the voltage changed on the T-con? I wonder if the values were incorrect from the factory or if they have been adjusted/corrupted at some point...

[ODDS]

Re: Samsung UH55H6400AKXXU Display Problem

Nice to hear it's fixed. Did you see if the voltage changed on the T-con? I wonder if the values were incorrect from the factory or if they have been adjusted/corrupted at some point...

Hi tom,
The voltages on the T-Con were the same when it was disconnected from the panel as they were when connected.
Given the purchase date that was in the Service menu (31/12/2014) it looks like a factory fault, and it was probably returned by the original purchaser.
Really pleased considering I picked it up for about 50% of the retail cost and it was only a few weeks old.
Thanks once again for your input.