Hisense (emerson) LTDN-42v68US no picture, yes sound

[ben7]

Re: Hisense (emerson) LTDN-42v68US no picture, yes sound

Yeah, don't think that is doable at my knowledge level.

On the other hand, I tested the FP1 with power ON screen lit up. With ohms set to 200, black on frame red at top of FP1 got 3.3.

I also volt checked the LVDS cable and the far right cable going into this screwed up tcon reads 11.89v with volts set to 20, black on frame and red on pin.

So maybe some hope?

How did you get 3.3v if there is a short to ground? I'm really getting confused.

[Jim1590]

Re: Hisense (emerson) LTDN-42v68US no picture, yes sound

I'm really getting confused.

That makes 2 of us. I did the exact same thing as previous test except power was ON for the tv.

Multimeter set to 200 (ohm x1), black lead against the frame red lead on FP1 top. Red on FP1 bottom was no reading. Now got 3.6 steady as noted, varies with how I hold probe.

Maybe I screwed something up before

[Jim1590]

Re: Hisense (emerson) LTDN-42v68US no picture, yes sound

ok ok my bad...

long day at work.

tv on VOLT reading at bottom of FB1 is 11.89

top of FB1 is 0.00

[ben7]

Re: Hisense (emerson) LTDN-42v68US no picture, yes sound

ok ok my bad...

long day at work.

tv on VOLT reading at bottom of FB1 is 11.89

top of FB1 is 0.00

Thats what I thought was going to happen. But I got confused, LOL.

There definitely is a short on the tcon, since the top of FB1 to ground measures about half an ohm.

[Jim1590]

Re: Hisense (emerson) LTDN-42v68US no picture, yes sound

Well I am not going to order that board. That would put me $100 into it with no clear idea how to attach it and no 100% sure another board is not acting up.

I would like to do 1 of 2 things since it is essentially trash with some boards I can pull. First, how bout jumping the fuse with a thin wire to each end and see if I get a picture for a few seconds.

Second, try my hand at replacing the fuse itself. I have a local store that does pcb parts that I can probably get one at. Just need to know what to get!

Thoughts?

Thanks

[ben7]

Re: Hisense (emerson) LTDN-42v68US no picture, yes sound

Well I am not going to order that board. That would put me $100 into it with no clear idea how to attach it and no 100% sure another board is not acting up.

I would like to do 1 of 2 things since it is essentially trash with some boards I can pull. First, how bout jumping the fuse with a thin wire to each end and see if I get a picture for a few seconds.

Second, try my hand at replacing the fuse itself. I have a local store that does pcb parts that I can probably get one at. Just need to know what to get!

Thoughts?

Thanks

I guess since the tv won't be able to be fixed with a new board, you can go ahead and jumper the fuse. If your lucky, it could be a shorted ceramic capacitor, or something simple like that.

[Jim1590]

Re: Hisense (emerson) LTDN-42v68US no picture, yes sound

Nothing changed with a jumper.

So I removed the fuse gonna see if I can get a new one. Should be pretty cheap. Nothing to lose now.

I think I can assume that since nothing changed once the fuse was out in regards to the symptoms, I can call the other boards working and sell them off if a new fuse does no work.

Thanks for the help.

[ben7]

Re: Hisense (emerson) LTDN-42v68US no picture, yes sound

Nothing changed with a jumper.

So I removed the fuse gonna see if I can get a new one. Should be pretty cheap. Nothing to lose now.

I think I can assume that since nothing changed once the fuse was out in regards to the symptoms, I can call the other boards working and sell them off if a new fuse does no work.

Thanks for the help.

Nothing changed, as in, you have sound but no image? It might be that whatever was shorted has now burnt open-circuit. Did any of the parts get hot?

[Jim1590]

Re: Hisense (emerson) LTDN-42v68US no picture, yes sound

Correct yes to sound no to picture. Same lit up black screen.

I did not leave anything on for more than the 2 seconds to see if it worked

[ben7]

Re: Hisense (emerson) LTDN-42v68US no picture, yes sound

Correct yes to sound no to picture. Same lit up black screen.

I did not leave anything on for more than the 2 seconds to see if it worked

Measure it again to see if the short is still there.

[Jim1590]

Re: Hisense (emerson) LTDN-42v68US no picture, yes sound

I placed one end of a wire on one end of the spot where fuse was and one on the other. Not secured or anything, joust resting there. Placed mm on ohm at 200 and (it jumped a lot, probably since nothing was really connected) and I was getting it to climb and climb up to 100+

So I am thinking that the board is otherwise good, but I am still out a fuse. My parts store does not have them and I still need numbers for that part of the board so I am not guessing on which fuse to grab. Guy behind the counter suggested a regular glass fuse and holder carefully soldered into place.

I can say that my above test is very hard to reproduce. Probably because I do not have anything really connected. I tried a bit of solder but I do not have a fine tip. Think it is not ensuring a good connection.

[ben7]

Re: Hisense (emerson) LTDN-42v68US no picture, yes sound

I placed one end of a wire on one end of the spot where fuse was and one on the other. Not secured or anything, joust resting there. Placed mm on ohm at 200 and (it jumped a lot, probably since nothing was really connected) and I was getting it to climb and climb up to 100+

So I am thinking that the board is otherwise good, but I am still out a fuse. My parts store does not have them and I still need numbers for that part of the board so I am not guessing on which fuse to grab. Guy behind the counter suggested a regular glass fuse and holder carefully soldered into place.

I can say that my above test is very hard to reproduce. Probably because I do not have anything really connected. I tried a bit of solder but I do not have a fine tip. Think it is not ensuring a good connection.

No, as before, the board is still bad. The shorted component is now burnt open circuit (high/infinite resistance)

[Jim1590]

Re: Hisense (emerson) LTDN-42v68US no picture, yes sound

ahh oh well. I will just part it out on ebay. I can probably be pretty confident the other boards are in good shape.

Thanks for the help. Maybe now I will look back at a 26" that has been sitting under the bed with a bad power up for the past year!

[Jim1590]

Re: Hisense (emerson) LTDN-42v68US no picture, yes sound

I heard back from a guy on ebay after a few days who is willing to carefully cut off his tcon and maybe I can splice onto my panel. But when wife got curious to what I was doing and I was showing her the issue she ripped a ffc off the panel. Is it fixable so I can try the splice, or is this panel ain't gonna work again.
Looks like it was held on by silicone only..... they must have saved at least $1.50 in making this thing.

[tom66]

Re: Hisense (emerson) LTDN-42v68US no picture, yes sound

No, that can't be fixed unfortunately. There's something like 300 precision aligned connections on that with 0.01mm spacing or something tiny, no way you'd ever line it up again properly.

[Jim1590]

Re: Hisense (emerson) LTDN-42v68US no picture, yes sound

thats what I was thinking

thanks

lesson learned, wife stays 10 feet away from all open tvs!