Toshiba 50HP66

[n3lka]

Hello all,

I have a Toshiba 50HP66 where it looks as if the picture is being squeezed into the middle of the screen. When it first turns on it looks as if there's a zsus failure, where as multicolored sparkles go across the screen. I get the bad picture when trying to bring the menu up. Sorry no pictures, it was kind of hard to get a picture of it with the set against the wall.

I checked voltages and it's all ok. And teh boards visibly look ok. I did a WCFT (well calibrated finger tip) measurement on the heatsinks on both the ysus and zsus boards. One of the zsus heatsinks is stone cold after leaving it on.

I'm thinking of throwing the dice and ordering a module for $40. Any one else ever have the zsus failure cause this issue for them? The last zsus issue I fixed was that I had a picture, but it was a snowy multicolored picture.

Thanks,Brian

[ReeceyBurger123]

Re: Toshiba 50HP66

Guessing its an lg panel, the Z mains job is to pre-charge and discharge the cells. When it fails it can cause glitches like described. More than likely the IPM under the heatsink has failed usual fault should be a fairly simple fix.

[n3lka]

Re: Toshiba 50HP66

For $40, I'll think I'll order the module. I already unsoldered it with my Hako gun. That's 75% of the issue with those modules, getting them out cleanly. I'll let everyone know how I made it. May be a while, ordering from China, I'll be a couple of weeks. Cheers!

[mmartell]

Re: Toshiba 50HP66

Better check the fets on your upper and lower y buffers for shorts. There are three on each. When they fail they squeeze the pic into a single line but maybe it's possible there are failure modes similar to what your describing.

Wouldn't hurt to remove them and check, I think they're on the underside of the buffers.

[n3lka]

Re: Toshiba 50HP66

Will do, I found a used module for $20. The original module was stone cold, where the others were warm. I will check the fets though, thanks!

Ordering the module soon, I'll post my results hopefully soon.

Now my Insignia is causing me grief by cycling power, started a thread on that one as well.

[n3lka]

Re: Toshiba 50HP66

Update, the module didn't fix the issue. I did find a shorted fet on the lower buffer as mmartel suggested, and it did fix the original issue. The parts just arrived from China, hence the long wait. Thanks mmartel!

However, it looks as if I have an intermittent zsus issue now which is probably from the used replacement I purchased. If the tv is on longer than 20 or 30 minutes, it will start to blink, show fuzzy reverse images, and then go back to normal, and start to blink. Luckily, I have a Hakko desoldering gun, so the original module is still usable. So I'm going to put the original module I pulled out, back in. The module I purchased was a "tested" pull from coppell. It was probably on tested for 5 or 10 minutes. So I lost $20, live and learn, although they do state they are used modules, so I'm not blaming them.

So tomorrow or Saturday, the original module goes back in. I took a chance on a used device, and lost. At the minimum, I thought I would have a spare module since it didn't fix the original issue. On the positive side, no more vertical bars from the bad fet.

[mmartell]

Re: Toshiba 50HP66

A member here tore one apart that was failing in this way and found dodgy carbonized connections at the igbt's iirc. If you're ambitious and/or bored you may be able to salvage it as a back up.

[n3lka]

Re: Toshiba 50HP66

Lol, maybe...but it was only 20 bucks. I'm hoping that's causing the new issues. But from the two zsus failures I've ran into, I have high hopes that the module is the issue.

As I said above, thanks for the heads up on the fet issue. I ordered 10 from China, so plenty of spares. They were pretty cheap too, just a long wait.

[n3lka]

Re: Toshiba 50HP66

Good news, the replacement module was the issue, or so it seems. I had it on for a good hour and no funny business. There's some slight red sparkles, but nothing too bad. It's a 10 year old plasma. I'll check voltages to make sure they're ok, other than that, spend an hour putting all the screws back in, and find a place in my house for the tv.

Thanks for the help.

[mmartell]

Re: Toshiba 50HP66

Good job. You probably know this but those three fets are in parallel and should all be replaced at the same time. Assuming the replacements from China are what they say they are it's just good preventative maintenance as the others could be stressed.

[n3lka]

Re: Toshiba 50HP66

Oh yah, all three were replaced and I still have plenty of spares.

Cheers!