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Toshiba 42HP66 Screen Blew

12820 Views 31 Replies 6 Participants Last post by  fhorn

I currently have a 42HP66 Plasma TV that I purchased 5 years ago.

I was watching TV the other night and I heard a click and the screen dimmed.

I shut if off and turned it on a few hours later.

The screen was still dim(very dark) and had black blochy spots that seem to receed a little.

I took a video of it. This is how dark the screen is now and you can see the black blochy spots:

Has anyone seen this before and know whats wrong?

Should I get it fixed or just buy a new tv?

Thanks for your time,
1 - 20 of 32 Posts
Ouch! More than likely it's one of the circuit boards inside the TV. Unfortunately I'm not that familiar with plasmas. Leonard should be along soon to offer some advice. If you're not comfortable fixing this yourself, find a local service center and have them do it for you.
Ok Thanks

Do you know Leonards nickname. i want to PM him and ask him to take a look at my thread.

Looks like a sustain problem, perhaps power supply to sustain circuit, but these are just guesses. I would get an estimate. You never know if it can be fixed inexpensively.

Sorry about the delay in reponse.
Thanks Leonard!

I found a guy that will fix it for $130!

I just hope its not a scam.

Hi everyone

I got the tv working.

I ended up replacing the zsus board for 64 dollars.

I knew it was the zsus board because one of the fuses burned out. The fuses had a white coating so I couldn't tell if they were blown. I had to do a conductivity test with a volt meter and sure enough one of the fuses were blown.

It could certainly be just a defective board. These circuits run hard, however, and power supply issues can contribute to their demise. It is always a good idea to check the power supply for filtering issues and to verify that the voltages are precise. Issues on the main board that affect the sustain waveforms can cause problems as well. These checks require some experience and a scope. The point is, don't be surprised if you have subsequent failures of the same circuit. Hopefully, you just had a bad z-sus.
I have the same exact set and, it had 1 blown fuse on the XSus. I tried simply replacing the fuse and there was a slight squealing noise but, still NO picture

Any ideas?

Also noticed that there are 4 Ceramic resistors which were squealing in the power supply area after replacing the fuse were super hot and actually melted the solder and became loose and fell out. (Burnt finger touching 2 of them, trying to locate source of squealing)

Possibly cold solder joints or excessive drain?

Any ideas would be greatly appreciated

Thank you

United Electronics
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Are you a technician?
I am not a very experienced technician

Only have basic knowledge but, willing to learn I am Autistic and, everybody thinks I am just stupid. I wanna prov them wrong

I probably would not need to be here IF I was a Real Good technician

I am not shy to ask some questions to learn

Thank you

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Hello Gentlemen ,

I am trying to find some tips for a LG 42LF11-UA LCD television with NO video

But, I cannot find anywhere on this site that deals with LG

Can anyone point me in the right direction

I have a funny feeling that I might just need a TConn controller but, there could be another problem


United Electronics
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We are happy to help you learn.

Please keep threads on topic and post new problems with different models in a new thread in the appropriate forum. It is unlikely that anyone with knowledge of an LG product will be looking in a thread about a Toshiba.

The reason I asked if you were a tech is that I saw your signature and wondered. An experienced tech would not just replace a fuse like this without doing some checking, and would know that a squeal is likely a switching power supply being heavily loaded down. Fuses don't blow for no reason, particularly those that are AFTER a regulated supply and have high current ratings. If the power supply is running correctly, there is almost certainly a problem on the Y or buffer boards, perhaps other or panel. A blown fuse is a good indicator of where the problem is, and one should start looking for a short that is capable of drawing a large amount of current BEFORE replacing the fuse. You run the risk of doing more damage by running the set, particularly running it to the point that the solder on the fuse melts.
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I can not find any LG thread. I apologize

I actually found out what was wrong. It was the YSUS and, I had another different set which used the SAME YSUS and, changed it and the set powered up. Now, I need to determine what could be wrong with the original YSUS.

Also, I just wanted to share this . There are 2 fuses on the YSUS and, I actually forgot to replace the fuses in it when I borrowed them for the other set and, when I powered the set on IT actually powered up and worked without them. I only noticed when I was removing it to compare the 2 that they were not there. Weird ??? And, when I replaced them the set still worked except with more color. So, I am wondering exactly what the function of those fuses are? They are surely not for power because the set worked or, powered on with graphics at least, without them

And, No, the solder melted on the 3 Ceramic resistors not, the fuse.

Also, in this set the YSUS is bad but, the buffers are good. kind of backwards huh?

Please advise


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Not backwards at all. YSUS boards fail all the time. Just because you have run across reports of buffer failures does not mean that that is all that tends to break.

Some of the first lessons that sucessful techs learn are to not make assumptions, use all available information, and narrow the problem with research, testing, and observation.
Looks like we need to create a forum for LG/Zenith. Post in the more general forum when in doubt. Do not add on to existing threads with new problems.
Looks like we need to create a forum for LG/Zenith
I do warranty work for LG also if it helps.:T
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