Rescued 2001 RCA 36" F36669 with rainbow

[pac.attack76]

Turns on and runs fine but I noticed discoloration at top right and bottom left of screen. Changes when I move it around the room. In another location, it was bottom right and bottom left. Any ideas?

[Eric H]

It needs the CRT Degaussed.

It's supposed to do it automatically every time it's turned on cold, but their could be something wrong with the Degauss circuit, or the tube could be magnetized to an extent that the internal degauss coil can't fix it, if that's the case you will need to use an external degaussing coil like this one:

http://www.ebay.com/itm/GSG-Televisi...item5b0ff860df

Another possibility is the Shadow Mask inside the CRT is damaged, this can happen if the set was dropped or knocked over at some point, there's no fix for that except a new tube.

[zeno]

Degauss thermistors fell apart left & right on these.
IIRC its near where the AC cord comes in. Dime sized
& has leads soldered to it. You can usually resolder the leads.
Also IIRC these had orientation switches on the back marked
E-W etc. Dont remember how to set them though

BTW whats the chassis number CTC###

73 Zeno

[pac.attack76]

ctc203c. It moves around the screen when moved as gravity affects it.

http://www.videokarma.org/attachment...1&d=1428772475

[zeno]

Thought it was the older chassis. IIRC the 203 was the
last real RCA chassis. Look near where the DGS coil plugs
in for the thermistor.

73 Zeno

[Celt]

Originally Posted by zeno

Degauss thermistors fell apart left & right on these.
IIRC its near where the AC cord comes in. Dime sized & has leads soldered to it.
You can usually resolder the leads.

Exactly!

[Findm-Keepm]

While you are in the TV, check the solder on the Pincushion board - that was the number one gripe we had with the '203 - bad solder joints causing all sorts of problems. IIRC, it's on the right side of the chassis when looking at the back of the set.

Cheers,

[rca2000]

And above ALL...the connections on the horizontal driver transformer path too !!

I would definitely try and degauss that tube. Those RCA tubes of that era are VERY reliable. a 207768 RCA part will replace the thermistor

[wa2ise]

The Earth's magnetic field could do that. Tap not real hard on the cabinet, and see if the false colors flap "in the breeze".

Do you hear a short buzz when you turn the set on when it's cold (ie, not been running for several hours). If not, the thermistor probably broke, and the set isn't doing a degauss upon power up.

[Electronic M]

A soldering GUN may also work as a degaussing coil in a pinch.

[Findm-Keepm]

Originally Posted by Electronic M

A soldering GUN may also work as a degaussing coil in a pinch.

+1 - I used to degauss computer monitors aboard ship with a Weller 8200 Soldering gun. For the 19" Zenith we had in the office, we had to use a degaussing coil. You can make your own - 22 gauge wire, 34 turns in a 12-13" diameter coil. I put a momentary rocker switch in mine - others use a plain rocker switch. Wrap the whole thing up in electrical tape, wire the switch in series with the coil, adding a 8' power cord. We extended our cord - sometimes when using in a customer's home, the nearest outlet was 1-2 feet beyond the cord length.

Where to get the wire? Junked BPC sets. Look for copper wire - aluminum wire heats up, and you don't want hot wire in your hands. If the connections to the coil are soldered, it's copper - for aluminum, they used crimps.


Cheers,

[pac.attack76]

Originally Posted by Findm-Keepm

+1 - I used to degauss computer monitors aboard ship with a Weller 8200 Soldering gun. For the 19" Zenith we had in the office, we had to use a degaussing coil. You can make your own - 22 gauge wire, 34 turns in a 12-13" diameter coil. I put a momentary rocker switch in mine - others use a plain rocker switch. Wrap the whole thing up in electrical tape, wire the switch in series with the coil, adding a 8' power cord. We extended our cord - sometimes when using in a customer's home, the nearest outlet was 1-2 feet beyond the cord length.

Where to get the wire? Junked BPC sets. Look for copper wire - aluminum wire heats up, and you don't want hot wire in your hands. If the connections to the coil are soldered, it's copper - for aluminum, they used crimps.


Cheers,

And to think, I just scrapped several from junk sets I scrapped out. I have a switch somewhere as well but not sure what type. Only iron I have right now is a $7 cheapo from Wal-Mart. need to upgrade on that soon. I wonder how many sets I'd have to tear down in order to have enough wire.

[Electronic M]

A big screen set's degauss coil should if looped down to ~14" should last a minute or two at line voltage before getting hotter than you want to handle.

If you take that and watch the temp it should work.

[zeno]

If you make your own coil you MUST put a
spring loaded switch on it. Once the boss degaussed a
set & just put the coil down. He ran an errand & when
he got back the place was full of smoke & the coil melted into the
set he put it on.
Dont get me wrong I am not a paranoid safety nut. In fact I
am always ripping off safety tags & those damn furniture
tags !!!

73 Zeno

[wa2ise]

You need to be sure that it's the right kind of thermistor. Some drop resistance when they get hot (used in PC power supplies), not what you want here. You want a thermistor that increases resistance when it gets hot. Any BPC set will have one (often enclosed in a plastic squarish box), and you could use its degauss coil as well.