TCL L65F3500FDS issues - Tcon, panel, or ?

[skkunx]

Took a gamble and bought this TV for 100 bucks because I wanted to have a go at fixing it

Initially:
The furthest right quarter-column of the screen was slow to update which resulted in a blur as the picture changes. Additionally, there is a flicker/pulse: starts fine, then goes "blink blink blink, smear and darken" wait 5 seconds, reset to "normal" image, repeat (see gif below).

The second quarter column, moving from right to left, is darker than the rest.

Since:
I've removed the back panel, and it appears that someone has been in here before. The screws to access the Tcon board were horribly stripped, but i eventually got them off.

I have been fiddling with the ribbon cables from the T-Con board and at the boards connected to the panel, very bottom edge of display. When I unclip the the on nearest furthest to the side (column with blur) I can find little pressure points that will move/remove the dark column.

Wiggling the other ribbon cables, on either side, and the same changes occurred. Interestingly, fiddling with R ribbon cables would affect L portions of the display. Further wiggling and prodding of the panel tab connections have caused blue vertical and noisy bands (gif). In that gif you can also briefly see the pulse issue mentioned above. Apologies for the weird angle, I have the TV face down on my table, on a blanket, and i took the video with it hanging off the edge a bit .

I have swapped ribbon cables around which has not affected the picture, so I don't think the cables are the problem. My amatuer opinion is that it is the Tcon board but I would love to get some feedback before I buy a board (v420hk1-cs5) for another 60-100.

[maxvalutech]

Re: TCL L65F3500FDS issues - Tcon, panel, or ?

Can't help but think you are being hopeful. In my limited experience if the bonded connections give strange outputs to screen when poked etc then they are the problem. No experience with the set and the big ones are unwieldy to work on but as the old saying goes "a picture is worth a thousand words".

[skkunx]

Re: TCL L65F3500FDS issues - Tcon, panel, or ?

There's actually not much "action" at the tabs. Shifting and wiggling the ribbon cables is where 98% of the action occurs. That blue\noisy distortion is worrisome though...

The proud part of me wants to risk it. But I'll be pretty mad if the new tcon board doesn't fix it.

Is there any way I can test the voltages at the tcon board to see if it's dead?

[maxvalutech]

Re: TCL L65F3500FDS issues - Tcon, panel, or ?

Yes its risk vs reward. Generally 12v goes to tcon and you can check this at the fuse thereon (both sides). Sometimes other voltages are marked at points on that board, you can also check any voltage regulators for correct output and also take and record gamma voltages which have to be linear. All connectors need to be checked and carefully cleaned, both ribbons and receivers, and reattached with guide stripes nice and even across connector.

[skkunx]

Re: TCL L65F3500FDS issues - Tcon, panel, or ?

Yes its risk vs reward. Generally 12v goes to tcon and you can check this at the fuse thereon (both sides). Sometimes other voltages are marked at points on that board, you can also check any voltage regulators for correct output and also take and record gamma voltages which have to be linear. All connectors need to be checked and carefully cleaned, both ribbons and receivers, and reattached with guide stripes nice and even across connector.

Probably too much for me to really accomplish with my limited understanding.

What would you experts do in this situation? Scrap it? Run more tests as above? Replace X, y, z?

[budm]

Re: TCL L65F3500FDS issues - Tcon, panel, or ?

Voltages testing is the minimum requirement. No Voltage No operation

[maxvalutech]

Re: TCL L65F3500FDS issues - Tcon, panel, or ?

A picture of your tcon would assist in getting help. Test points for gamma may then be seen and the fuse will be near connector for lvds strap coming from main board. You do have a multimeter? They are cheap. You will need to search for a tcon at the right price and TCL may have to look at China outlets Aliexpress DHGate etc. Having a go can be a trial so much to cover and all new but it gels after awhile and there are feel good moments when it comes together.

[skkunx]

Re: TCL L65F3500FDS issues - Tcon, panel, or ?

Attached an image of my tcon.
I do have access to a multimeter, but I can't say that I'm incredible well versed in how to use it. Nothing an hour on YouTube cant change though.

There's an Australian option to buy at 100 (less than a week to arrive) or an American option at 60 (up to a month to arrive)

[maxvalutech]

Re: TCL L65F3500FDS issues - Tcon, panel, or ?

Getting there. The screws should all be put firmly back into the tcon as they act as earth points. The lead to con1 needs to be closely examined for any damage and correct fitting. Looks like the gamma points are marked but would like someone more experienced to add comment and point you to how to measure. Keep at it.

[Davi.p]

Re: TCL L65F3500FDS issues - Tcon, panel, or ?

Getting a giant broken tv and spending money, time and space with no knowledge is crazy, one have to begin with no price monitors, then move to small tv, then bigger ones...
From your animated gif is not possible to understand the problem, too poor... but if my english works a bit and from your description leave to stay the option to waste money on a TCON board, much probably you have broken traces on a panel's tab bond, you could fix it with a flyng wire soldered between horizontal tab and side tab, but is a very difficult task, if you want check my thread about Sony KDL-60ex700, that may be the same problem.. you can also have the luck to fix with a shim on the tab..

[maxvalutech]

Re: TCL L65F3500FDS issues - Tcon, panel, or ?

Davi.p on pure economics is right but there is more to it than that. You have expended $100 but in worst case could probably recover that from sale of boards and remote if you got one with it. In for a penny in for a pound is the old saying but don't throw money at the set. Your tcon board is in many makes of set BUT the white sticker has a part number which good sellers will quote. Prices I've seen are from $20 but watch postage costs. I've had parts from Poland, UK, US, but mainly China Hong Kong (which is where the board is made). However, again Davi.p is probably on the right track and you need to do the testing and fiddling first. People spend time and money on various pursuits e.g. how much for a game of golf ? which can be just as frustrating ! For myself I'm just trying to keep the old brain active and I find that with sale of sets I do fix that at worst I break even.

[Davi.p]

Re: TCL L65F3500FDS issues - Tcon, panel, or ?

But 65" is a damn giant tv, it joins unconfortable handling and difficult tech aspects.. apart that i don't know which dollars are 100$, US or AU..
I feel frustrated many times trying to fix TVs and i'm on this field since 6-7 years, i think one novice which obstacles meets on the way, if it has not passed the "mess tin".

[maxvalutech]

Re: TCL L65F3500FDS issues - Tcon, panel, or ?

Yes Davi.p I haven't had one that size to work on as yet but they are coming!! First 50" I got managed to drop it and break screen. Here in OZ the shops tell me everyone wants the big sets now 65" - 75" and are putting the little 50" in the bedroom!! Talking Aus dollars about 75c US.

[Davi.p]

Re: TCL L65F3500FDS issues - Tcon, panel, or ?

Also different models are different weights, i have on 40" that weights much more than a 50" and both are last generation sets.. Handling a 60" Sony by myself was a pain...

[skkunx]

Re: TCL L65F3500FDS issues - Tcon, panel, or ?

Yes, I recognize that I bit off more than I can chew; and I don't have the capacity/patience to test every little connection. I am going to just try to sell as is.. and if i get no offers then I will make a further decision to either harvest for parts, or buy the Tcon board and hope for the best.

This gif more clearly shows the problem(s).


again, using the highly accurate manual wiggling/prodding technique:
-movement at the panel edge tabs does nothing
-wiggling the ribbon cables at the connections changes and erases the display issues, but never to a point where the whole display is in perfect working order.

[freakaftr8]

Re: TCL L65F3500FDS issues - Tcon, panel, or ?

That's tcon failure! Look at the sharp I replaced the tcon on the other night. Now after the tcon replacement it flickers every once in a while which I believe may be panel failure ( side gate tabs)

I believe the bad gate drivers probably took out the original tcon

[skkunx]

Re: TCL L65F3500FDS issues - Tcon, panel, or ?

That's tcon failure! Look at the sharp I replaced the tcon on the other night. Now after the tcon replacement it flickers every once in a while which I believe may be panel failure ( side gate tabs)

I believe the bad gate drivers probably took out the original tcon

Motivating me to just replace the board.

If I was in the US, it would cost me next to nothing, and take me all of a week to order, receive, and swap it in. Stupid Australia.

[maxvalutech]

Re: TCL L65F3500FDS issues - Tcon, panel, or ?

I buy very few parts here in Oz as asking prices are ridiculous. I'm now quite used to waiting 4 - 6 weeks for delivery of parts sourced overseas. With a big set just store it under a bed or wherever while you wait.

[Davi.p]

Re: TCL L65F3500FDS issues - Tcon, panel, or ?

Then.. forget what i've said on the defect, i'm not sure on which is this one, not so common, but i suspect also to be the mainboard. If i have time i can search the forum for an old thread where i have seen something maybe interesting. At first sight it seems a tcon/panel problem but on some newer design how is, how don't is, it can be the mainboard, please first check inside which is the producer of the mainboard and also the main chip of the mainboard... see you later..

[Davi.p]

Re: TCL L65F3500FDS issues - Tcon, panel, or ?

In this thread: https://www.badcaps.net/forum/showthread.php?t=66084 ,
you can see that what it seems a tcon problem (screen divided into 2) is in fact a mainb. one, you can do the test of that user, unplug the tcon lvds cable and see if a self test appears.. Anyway if you say that dismounting the screen bezel and touching screen tabs makes big difference in the video then is a screen problem..