Odd tv problem

[famiac]

Hello, i have a sharp 19sv11 known as the nes tv along with the sharp 19sc11. It has an odd problem: There is a red splotch of color on the top left, and a green/blue one on the top right. The red one is much bigger. I tried degaussing the tv, but it did nothing. I messed around with magnets and i managed to get rid of the color splotches when i had the magnets in a certain position. Anyway, i found that rotating the tv counterclockwise fixed the problem. But it only works properly when facing that one orientation.... I moved it to another room and had the same problem. Even worse is that when i fixed the problem, after a few hours it came back and i had to rotate it again. Can anyone help?

Thanks.

[Frank_fjs]

First thing that popped into my mind is to give it a degauss, but you mention you tried that with no success. Are you sure your gun is working correctly?

Your problem sounds like it could be related to some form of magnetic interference - this could be caused by anything I suppose, perhaps you have electrical/telephone towers etc nearby? I'd keep trying different rooms to see if you can find a sweet spot.

[133MHz]

i found that rotating the tv counterclockwise fixed the problem. But it only works properly when facing that one orientation.... I moved it to another room and had the same problem.

That can be perfectly normal. CRTs are very sensitive to magnetic fields and the Earth's magnetic field affects them considerably, especially with larger size tubes. Some CRTs are affected more than others and it might be completely normal to have purity and/or convergence errors if the CRT is sitting in a particular orientation which go away if you rotate the set. My arcade cabinet for example likes to sit parallel to North/South, if I rotate the cabinet so that it faces East/West, uncorrectable purity errors appear on the screen. The 'solution' is to leave the cabinet or monitor in its preferred orientation.

Even worse is that when i fixed the problem, after a few hours it came back and i had to rotate it again.

This has left me completely dumbfounded. That should not be happening unless there's some strong external interference like Frank_fjs said or if there's something really wrong with the tube or chassis. The problem shouldn't come back on its own, I've never seen anything like this before!

Could you post a picture of the problem over a completely blue or red screen? (the usual blue screen that VCRs put out when not playing a tape and not tuned to anything will do nicely) so I can try to judge the severity of it. Also, what are you using to degauss the set?

[famiac]

Ill try to degauss again and move rooms and post back with pictures.

[famiac]

Im need a new degaussing coil... Does anyone know if radioshack sells them? I dont want to have to wait for ebay...

[security16]

That actually sounds like the beginning of the end for the picture tube in the tv but i could be wrong

[famiac]

I just picked up the tv from the damn repair shop... I'm pretty furious.

[famiac]

Convinced it's a degauss problem. Im going to go get a proper coil soon.

[133MHz]

What were you using to degauss the tube before? I have a small degaussing coil made out of a coil salvaged from a scrap PC monitor and I found out it wasn't powerful enough to degauss a large and vintage Sony TV I restored last year, only the huge built in coil was able to fully demagnetize the tube.

I think you should give the repair shop a call, maybe they screwed something up by mistake and in that case they should respond for it.

[ericj]

I agree with 133. If you had it in for repairs (this is the TV that arrived all fucked up from shipping, right?), then they need to fully fix it. No need for you to troubleshoot it.

[famiac]

Sorry i ignored this thread. The display must have got messed up during the drive home. I was doing some maintenance on the nes part and it turns out there was a looose piece of metal flying around in the tv. Because i heard some rattling when i stood it back up and the problem totally solved itself.