Entertainment Center: TVs, Stereos, VCRs and DVDs - Odd picture problem on Mitsubishi CS-40809

Hi, I have a nice '98 Mitsubishi CS-40809 40" direct view TV, but it has a problem. It has some wierd images in the screen, like they're burned, but not the same. There are some white ghost like lines that run vertically a few inches or so wide in a few spots. They aren't even like lines in the picture going out though. Anybody know what this could be? If you need more description please let me know. Thanks

Good Afternoon, TRUEDIABLO:

That's an interesting description. It sounds like a thing we call
"snivets" which are caused by a high voltage arc inside the set.

WITH THE SET TURNED ON:
Let's do the sniff test! When high voltage arcs, it develops a smell of ozone and have a definite odor at the rear of the set.
Smell anything unusual?

Now, let's do the listening test: When high voltage arcs, it usually has a definite "hiss" which can be heard at the back of the set. Hear anything?

Let me know what you find. If this is the problem, it is an easy fix.
We just have to make sure you don't get tangled up in the high voltage, though. It will jar the fillings in your teeth, believe me!

Smokey ;)

Well my sense of smell isn't the greatest right now, but there is a little something I could smell, not too strong, but I am kind of stuffed up. There was plenty of noise, the typical high pitch sound, and then a hum kind of sound. Does this sounds right? Also, I'm not sure if I made it clear, the lines don't move any, they're always in the same spot. Thanks for the help and info, let me know. Thanks

Good Afternoon, TRUEDIABLO:

Sorry to hear about the stuffy nose.

But, it does sound more like a high voltage arcing problem. I would make a guess that it is the connection to the picture tube is not seated properly.

Of course, the only way to make sure is to take the back off the set and have a look. MAKE SURE THE SET IS UNPLUGGED!

Once the back is off, you can see a rather large wire connected to the glass of the picture tube. This is the high voltage wire and usually has a rather large rubber cup covering the connection.
CAUTION! This spot is holding about 40,000 volts even with the set off. The wire is normally located on top of the picture tube and centered on the glass.

To discharge the picture tube high voltage, I always used a clip lead and a long screw driver. Clip one end of the lead to chassis ground and the other to the shank of the screw driver. Gently slip the screw driver under the rubber cup of the high voltage lead. YOU WILL HEAR A LOUD SNAP WHEN THE HIGH VOLTAGE
DISCHARGES TO GROUND. It may startle you a bit so be aware of it.

Once the tube is discharged, there is no more danger of getting knocked on your posterior. Then you can lift the rubber cup and check the lead to make sure it is secure to the picture tube. And make sure the rubber cup sits securely on the glass when you are done.

If this all sounds too scary, then it is time to call out the technician.

That's the best I can do for you from a forum standpoint. Good luck and good hunting.

Smokey ;)

Okay, I'll give that a try and let you know how it goes. I am a little scared of the electricity in there, but think I understand how to do it, except for where to ground it, is it obvious where on the chassis is grounded? Will just any wire with clips on either end work clipped to a screw driver? Of course hold the plastic hand on the screwdriver too? Thanks for the help.

Good Morning, TRUEDIABLO:

Yes, any clip lead will work and wire size is not important. There is no current involved.

Television chassis ground is usually just any metallic support or metal area you can find. It isn't hard to identify it.

Good idea about the plastic handle on the screwdriver. The picture tube is like a large capacitor (condenser) and stores voltage for a long time after the set is turned off. It takes a couple of days to bleed the voltage off after the set is turned off.
While it will not kill you, the jolt will rattle the fillings in your teeth and is not a pleasant experience. Discharging the tube will solve all of that.

Smokey ;)

Now I looked at it, and it's the thick wire to the top of the tube like you said, I see it, but where do I touch it? Under the rubber cover? or just anywhere on that part of the tube? Thanks

Good Evening, TRUEDIABLO:

If you discharged the picture tube as we discussed, then it is a simple task to remove the lead from the picture tube, check it out, and re-install it. As I said before, the actual connection to the picture tube is under the "rubber cup".

I know this is a mute point...but: did you turn on the TV with the back off? See any sign of arcing of the high voltage? Around the big wire we discussed? Hear any hissing sounds?.

A little visual and one-on-one with these things helps to pinpoint the problem.

Again, remember I am sitting at a computer a bunch of miles from you and am only working with best information on your problem.
This is not a perfect science, you know.

Smokey ;)

Yeah, I knowwhat you mean. I didn't try turning it on when the back was off. Where do I touch the screwdriver to make the discharge? Somewhere near to the big wire I'm going to be taking off, just on the tube? Thanks again.

Good Morning, TRUEDIABLO:

Well, you can see where the wire connects to the picture tube and can usually see a large rubber cup covering the connection.

As I said before, slide the grounded screwdriver UNDER the cup
toward the center. When the screw driver contacts the connection on the picture tube, you will hear a loud 'SNAP' as the picture tube discharges. Again, all of this is done WITH THE SET OFF AND UNPLUGGED.

Smokey ;)

Ah, okay. I'll give it a try. Thanks for all the help and advise.

Good evening, TRUEDIABLO:

If you get faint of heart, my friend, then stay away from it! Call the technician out and tell him you have "snivets". He can take it from there.

I'd rather you did that then get knocked on your posterior. Hey, we need all the members we can get on this forum. If we get enough members, they promise they might pay me someday for sitting here answering these questions. LOL! Yah, you guessed it! We're all volunteers and work for nothing.

Smokey :)

Hi, well I finally got around to trying that, I unplugged the TV a couple days ago to let the power start draining out, and then did the thing to drain all of it (there was none left though). I pulled the thing out of the top of the picture tube and checked it out, then put it back in and made sure it was all seated right then put the back back on and plugged it in. It didn't fix it though, the same lines are still there and at first there was a new line that was horizontal and ran down vertically. Any ideas?

Good Morning, TRUEDIABLO:

I still am of the mind that it is an arcing problem. Can you run the set with the back off? Turn the lights down low (or off) and you can usually see a bluish corona where the HV is leaking to the air.

Hear a "hiss" from the back while it is running (doesn't have to be very loud).

The reason I am questioning this is because at the other end of the wire to the picture tube, there is the HV power supply. The
arc could be coming from that area, also.

Remember, just observe and don't get near it. It will light up your life.

Smokey ;)

So from either end of that wire it could be 'leaking' power? I might try it, again, I'm leary of running it with the back off, I actually didn't really look at the bottom end of the high voltage wire, I think it's pretty well seated at the tube end though. I'll try listening again to the back for noise and smell as well and see. Thanks for the help, I'll keep you posted.

Good Evening, TRUEDIABLO:

This thread is getting too long. I am closing it. Come back with a new thread....please. But, we have forum standards we have to follow .

Thanks for using DoItYourself.com


Smokey ;)