Hisense 50P6

[snowangel27]

Re: Hisense 50P6

update....still working after repair

Please take a look my theard
https://www.badcaps.net/forum/showthread.php?t=124448
Maybe i should check the eds diodes on buffer boards again

[viewerau]

Re: Hisense 50P6

update....still working after repair

[viewerau]

Re: Hisense 50P6

I removed the diode chip next to the one previously removed, the tv is back to working in all areas again, no picture problems now.

Special thanks to ruckusman.

[viewerau]

Re: Hisense 50P6

Just adding to this, unsure if it should really be a different thread? If so, please advise and I will repost it there.

In regards to these edge boards on tv panels, why do they insist on making them so that they are permanently fixed (bonded) via cof to the panel itself?

On all the other parts of the panel, the tcon, main board etc all use the little clips to undo and disconnect them, so replacements can be fitted.

Why can't the same be done to edge strips? I can understand the strip itself being bonded to the panel, but if the connection between the edge board and the cof strip were the same a tcon connections, surely many panels could easily be substituted/repaired, in a very easy fashion?

[viewerau]

Re: Hisense 50P6

I wonder if it is the diode on the same end to remove, or one of the two on the other edge board?

When I tested all four diodes, the one that was removed was the only one showing a fault.

[nomoresonys]

Re: Hisense 50P6

Well as per post 140, BOTH esd diodes were shorted, may be your problem too? you will not lose the picture if you remove the other one, just be careful not to damage anything during removal.

[viewerau]

Re: Hisense 50P6

I cleaned all my desoldering with isopropyl today...it is nice and clean, but unfortunately, I still have the little 3 second micro busrt happening at the bottom of the picture......suggestions please?

[viewerau]

Re: Hisense 50P6

Update....

Hi again,

I spent around 2 hours reseating and wiggling all the tcon and cof strips, but I cannot stop that pulsing loss of video on the last bit of the screen.

I did note that when I had my finger on the spot where I removed the D004 chip, that I could feel voltage on my fingertips...like heat.

I took out the solder iron again and used some more solder wick to clean the area, just in case there was still some solder residue etc, but that also didn't seem to stop it.

I'm sort of reluctant to want to try to remove another chip, as if I do so, and it ends up with no picture etc, then there is no way I can put a replacement chip in it's place.

Any suggestions please?

So close...yet so far !!!

Thanks

[viewerau]

Re: Hisense 50P6

Just in case you cannot see the video.

[viewerau]

Re: Hisense 50P6

Hi all.

I have not had time to try to fix this issue, however, user ruckusman sent me some detailed information regarding the removal of one of the diode chips (D004) from the edge board.

I did this today, instant success, in that everything boots up and it now displays everything.

The only hassle I have is to now work out why I get some intermittent lines flashing on/off at the bottom of the screen.

Well done ruckusman....you were 100% spot on with your analysis.

Video https://streamable.com/6rcwwz

[ruckusman]

Re: Hisense 50P6

They're tiny aren't they...

Leave the edge boards all connected up, including all t-con ribbons.

Don't worry about the diode function, just test each pin for short to ground.

They are 5 connections going top to bottom on them - the centre pins are going to ground - top and bottom - use those pins to check the continuity to ground on the meter.

So if you can put one lead to the metal chassis of the screen [ground] and test the two outer pin pairs, one at a time across both the top and across the bottom.

Check my thread for which pin was short, it was pin 2 - counting left to right with the type right way up.

Yours may be different if there's a short on another pin, it was just one short, one short on each of two diodes on my unit that stopped it working.

[viewerau]

Re: Hisense 50P6

I am unsure if I am doing things right or not, but tried to help myself again, so I could offer up some results for comment.

Boy are those diode things small!

At this stage I just ensured the power was off and I got my cheapo multimeter into diode mode.

With the edge boards in place (it'd probably be easier with them out of their clips) I found that by trying to put the negative probe to the top of the array, and hoping to make a connection to opposite legs with the positive probe, I find I did get some readings.

The 4267H on the board that is last, which is for the right side of screen, they both gave gave numbers around 1433-1436 and then dropping, and the one's on the right, gave numbers of about 1000 and dropping.

I will try again tomorrow, as it was very difficult to try place a bright led light on the board, position a magnifier glass, and also place the probes on correctly, as the bottom legs were hard to see whilst it was all held in place.

Should each pair of legs give a reading, and is it necessary to measure them with the probes set all one way (ie negative to top and positive to bottom), or both ways. Should each set of legs show the same values etc

Thank you

[viewerau]

Re: Hisense 50P6

This is the end of each board..which to check?

I have found I have to have all power off when checking a diode.

Mine appear to be marked 4267H, and there are two of each marked DOO3 and DOO4

How do I actually check them please?

Thank you

[viewerau]

Re: Hisense 50P6

Thank you.....
2 questions please...

1)How do you remove the speakers that are seemingly fixed with blue round fixings shown in post 5, image 1

2)When the edge board is fully exposed and I measure the diodes you say, do I do this with power off/standby/power on?

Thanks

[ruckusman]

Re: Hisense 50P6

Sorry, I just realised that post #150 shows a different t-con image than what is mine.

I got that image off the net.

This is my board.

Maybe the vgh or vgl has to be on the edge boards and not the tcon?

If I wanted to try a tape method to see what that would do, which pins would I need to block off on either tcon strip?

Thanks

That's your 'edge' boards in that shot [I assume that shot is inverted] - they are connected to the t-con by the ribbon cables you've been having issues with and they run along the edge of the screen.

Find the protection diodes on those edge boards and check them for short circuit to ground.

[viewerau]

Re: Hisense 50P6

Sorry, I just realised that post #150 shows a different t-con image than what is mine.

I got that image off the net.

This is my board.

Maybe the vgh or vgl has to be on the edge boards and not the tcon?

If I wanted to try a tape method to see what that would do, which pins would I need to block off on either tcon strip?

Thanks

[viewerau]

Re: Hisense 50P6

Thanks Diah...do you mean to do this test again ...


if yes then do the test i mentioned...
feed the F1 on T-CON 12V from power boards while the LVDS always disconnected from T-CON side... tell us what do u have on screen

[Diah]

Re: Hisense 50P6

with new ribbon cable. if you do the stand alone test.. do you have correct panel pattern color or not ?
i would suggest dont play with ribbon any more.... keep them plugged in to avoid damage them again.

[viewerau]

Re: Hisense 50P6

This is what I can see at present

[viewerau]

Re: Hisense 50P6

Thank you rucksman.

I don't have the edge boards fully exposed, as the bottom section of the bezel is still in place.

I can see two of the boards connected directly to the panel via that bonded tape, but perhaps there are two under the bezel as well.

I'll delve into those tomorrow and see what I can, and report back.

Thank you...everyone helping is greatly appreciated.