Hisense H55U7BUK - slow to load image

[djmka]

I have a Hisense 55" H55U7BUK television which has a very strange issue. When you first turn it on the the Hisense logo page appears as expected, then an image appears with the top 25% of the screen displaying correctly and the remaining 75% as if the T-Con is faulty (i.e. it has vertical lines). The screen then starts to recover the missing 75% line by line, taking a minute or so, until you end up with a great picture (please see attached photos). FYI - I've tried replacing the T-Con board but get the same results.
Has anyone seen this type of issue before?

[CapLeaker]

Re: Hisense H55U7BUK - slow to load image

What does the OSD look like?

[djmka]

Re: Hisense H55U7BUK - slow to load image

It appears the same way (please see attached picture).

[dskall]

Re: Hisense H55U7BUK - slow to load image

Looks like panel problem.

[djmka]

Re: Hisense H55U7BUK - slow to load image

Would a faulty panel “repair” itself like mine does? I was wondering whether it could be a power issue causing the problem. Are there any tests I can do to identify the root cause of the issue?

[dskall]

Re: Hisense H55U7BUK - slow to load image

Looks like maybe a cof tab issue. Maybe getting poor contact to glass. Squeezing the tab to glass on lower cof tabs to see if you can affect problem.

[Davi.p]

Re: Hisense H55U7BUK - slow to load image

Post picture of the tcon. 4 posts only and not a greeting? Not so well..

[djmka]

Re: Hisense H55U7BUK - slow to load image

Please accept my sincere apologies if I’ve caused offence. It was not my intention - honestly

[Diah]

Re: Hisense H55U7BUK - slow to load image

since the t-con are cheap i would suggest you to replace it.. its drop down current at it... later hisense didn't used external t-con because of many fault happened within 4k series

[Davi.p]

Re: Hisense H55U7BUK - slow to load image

my doubt and clue is very faint... taken in to consideration that electrolitics faults are much less common nowadays, but in the small case that a bunch of brands suffers still today of that, an electrolitic that works bad at cold and it works at the same frequency of the vertical of the screen, typically 50/100hz, can shorten the lenght of the disturbance until disappears.. but since the only part affected is the images i had guess it is on the tcon.. can you favourite the photo?

[lotas]

Re: Hisense H55U7BUK - slow to load image

T- CON found on the net for Hisense H55U7BUK.
https://www.tvparts.co.uk/lcd-tv-spa...sense-h55u7buk

[djmka]

Re: Hisense H55U7BUK - slow to load image

Thanks you to everyone who has responded so far. I have realised that I should have told you the history of the television first (apologies for not having done so). I bought is as a non-working device. It powered up but showed coloured vertical lines on the screen, some thin, some wide. I know this issue was related to the T-CON so I decided to identify which pins of the LVDS cable were causing the issue. Through a process of trial and error, I masked off some pins and the screen started working properly, albeit with the slow start up issue. Next, I checked the part number of the T-CON only to discover it wasn't the correct one. I ordered a replacement, (funnily enough it was from the supplier that lotas suggested) and when it arrived I installed it without masking off any pins. I got the same vertical lines as before. When I masked off the 4 or so pins, the screen started working (again, albeit with the slow start up).
Using either of the T-CONs and the tape, the televison's display is fine once it's been on on for a minute or so. If I power it off and on again the display is perfect immediately. This makes me think that something is taking its time to "warm up" but once it's warm it operates as expected.
Could it be a voltage issue on the power supply?

[Davi.p]

Re: Hisense H55U7BUK - slow to load image

do this test, at cold tv, warm up the AUO chip N7 with the soldering iron, then turn tv on an tell me..

[dskall]

Re: Hisense H55U7BUK - slow to load image

So if you are masking off pins that means you have a panel problem.

[Diah]

Re: Hisense H55U7BUK - slow to load image

checked the part number of the T-CON only to discover it wasn't the correct one.

it could be firmware on T-CON didn't matched main firmware... go to this side PW Hisense1234

download firmware lower than yours, i suggest the first version of any J firmware... then downgrade it... remember each time you downgrade or update log in service menu make hard reset ( clear chip )

[Davi.p]

Re: Hisense H55U7BUK - slow to load image

if the problem would be a wrong data in the tcon by changing it the problem disappeared but not, other than this if the previous owner have bought a spare tcon it is because the original problem is another...

[djmka]

Re: Hisense H55U7BUK - slow to load image

Message for Davi.p - when you say heat up the AUO chip N7 - how long should I leave the soldering iron on it?

[djmka]

Re: Hisense H55U7BUK - slow to load image

Issue now resolved. I bought a second t-con from tvparts.co.uk and I’m pleased to say that this one worked. My television is working perfectly now. Thanks to all who contributed.