Hisense 50P6

[viewerau]

Re: Hisense 50P6

Thanks ruckusman.....I saw the information and the red circled diodes in your other post.

So far, 5 mobs from AliExpress and Ebay have told me that they don't have the cable/ribbon with the same written specs.

If I get to the set still not responding after all the effort others have put in for me so far, then I guess that I just have nothing to lose in trying to remove those diodes.

I am not the smartest with a soldering iron, but do I just heat the iron and hit the solder on the rear of the diodes to get them to come off?

Thanks for thinking of me....cheers

[ruckusman]

Re: Hisense 50P6

I predict that if you check them, you will likely have a short as I did.
Those components prevented my unit from displaying a correct image, I had precisely the same symptoms as you, the lines up the screen.

You'll need a magnifiying glass to see the solder point to test them.

The centre pin is ground on both sides - all of the others pins 1, 2, 4, 5, 6, 7, 9 and 10 should not go to ground in a short circuit.

The diodes are tiny SMD components, for the time and effort that you've put in it's worth getting a hot air pencil, they aren't too expensive nowadays.

I have one similar to this one, from well over a decade ago, when I first got it I found the temperature as tested to be very accurate, it has served me well.

https://www.aliexpress.com/item/1005004961381060.html

Others may have other recommendations.

You can trim your cable by just a few Millimetres if you're careful.

Like in that video you posted, remove the blue plastic, then carefully in several passes cut the few milllimetres where the tracks have lifted, then reattach the blue plastic stiffener.

Once you've achieved that, I would remove the t-con, insert that end carefully, close the clip and do not remove that cable end again.

[viewerau]

Re: Hisense 50P6

I predict that if you check them, you will likely have a short as I did.

You can trim your cable by just a few Millimetres if you're careful.

Like in that video you posted, remove the blue plastic, then carefully in several passes cut the few milllimetres where the tracks have lifted, then reattach the blue plastic stiffener.

Once you've achieved that, I would remove the t-con, insert that end carefully, close the clip and do not remove that cable end again.

Thanks a lot....what setting do you use on an elcheapo multimeter (no beep function), and is the power to be off, and ribbons undone from tcon?

Lastly, the ribbon that is damaged cannot be shortened, as how it is now, there is no play between connections....the only way to do it, would be to unscrew my tcon from its existing position, and somehow mount if further down, and not in the existing place

[ruckusman]

Re: Hisense 50P6

Thanks a lot....what setting do you use on an elcheapo multimeter (no beep function), and is the power to be off, and ribbons undone from tcon?

Leave the ribbons connected to the t-con, then you can use the TV back panel metal as ground.

It makes it much easier as the diodes are so small, you don't want to be managing two multimeter leads whilst trying to touch each pin on the diodes and only one pin at a time if possible.

Meter set to diode test if you have one, that may give you a red led indication.
Otherwise the lowest resistance value and if it's short circuit to ground you will get zero ohms resistance.

Lastly, the ribbon that is damaged cannot be shortened, as how it is now, there is no play between connections....the only way to do it, would be to unscrew my tcon from its existing position, and somehow mount if further down, and not in the existing place

Have you gone to a local TV repairer that keeps good parts from unrepairable TV's as spares to see if they have one?

[viewerau]

Re: Hisense 50P6

I am again blessed. The person whom supplied me with the donor boards has been able to grab the two ribbon cables for me

I am fortunate to have his assistance.

They are in the post to me, and I will respond here in due course.

[viewerau]

Re: Hisense 50P6

Strips arrived this afternoon....hopefully try tomorrow.

[viewerau]

Re: Hisense 50P6

OK...

My new findings.

With power disconnected...

Fitted new strips to go between t-con and edge strips
1)Obtained backlights only, no picture or stripes on tv

I then turned off, and disconnected the strip between the tcon and the edge board that feed the right side when looking at the tv
I connected the power
1)No change, backlights only, no picture or stripes on tv

I then powered off again, reattaching the right hand ribbon to the edge board, and unclipped the strip feeding the left hand of the tv.
I connected the power
1)Obtained backlights again, then the picture changed to these images, cycling through all the time, in a slow fashion.

In every instance, as the tv responded to the remote to turn it on, the red standby light flashes 17 times on start up.

The pictures attached show what happened on the screen when the left hand ribbon was disconnected from the tcon board.

Doing some other reading, many sites suggest I check the VGH/VDD/VGL levels on the tcon, with strips on and off to the edge boards, to try to ascertain whether their is a short on the panel from a low/missing VGL. Thus I have soured my tcon board looking for these test points, but cannot find them. Does this find like I should be trying this as well, but what happens when I can't find them on the tcon boaard?

So different reactions to my initial tests, but am still at square one....STUCK.

[ruckusman]

Re: Hisense 50P6

17 flashes is normal, mine does that when working properly.

Your symptoms are similar [identical] to mine.

I scoured my t-con for errors [incorrect voltages - one was a negative voltage source, which was correct and near zero, two others with effectively zero voltage which was protection mode - the incorrect voltages on the t-con was a symptom of the blown diodes, NOT the actual cause of display issues], you can measure the voltages at each inductor but I suspect you're dealing with blown diodes also.

Check my thread again for the details.

Now do you have u-ribbons?
Meaning are there two separate boards on each side feeding the screen [4 in total].

If so you can try leaving BOTH t-con connectors installed and unplug the u-ribbons between the edge connection boards one at a time.

For me this was inconclusive as I didn't get an actual picture, BUT I did get the lines up the screen whereas I'd only had backlights only previously.

My diodes on the edge connection boards were on the end of the left and right outer end connection boards - you'll need a magnifying glass to see them, as although they've got 10 pins [connections] they are the size of a flea, literally.

Mine were both labelled D001, there may be more than one diode on your outer edge boards - check them all if there are.

Remember the centre pins [upper and lower] on the TVS protection diodes are ground and any of the other 8 pins which goes to ground is a short.

With one blown diode removed and the other outer edge board u-ribbon disconnected, I still didn't get a correct image, then once I'd removed the second blown diode all was well.

I was expecting to have to deal with other blown components, so that was pleasant surprise.

good luck

[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.

[viewerau]

Re: Hisense 50P6

This is what I can see at present

[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

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

[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

[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

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

[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

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

[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

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

[viewerau]

Re: Hisense 50P6

Just in case you cannot see the video.