This one was dropped on the bottom left corner by the looks of the
cracks in the case. Now it has bad purity down the left side, and the
bottom right corner. I have found some info on the net here;

http://videotech.lesterville.com/sony.htm

I thought I would check here to see if there are any alternatives to
trying magnets etc to get the purity back. I seem to recall that the
rings on the neck of the CRT used to be used for purity too, but these
ones have not moved.

Thanks,

- Tim -

Hi Tim

I think you have a CRT trouble. Inner CRT hole mask may be out of position or deformed because dropped. Sometimes after a big hit, purity and/or rainbow patterns appear across the screen. There are no ways to fix this kind of patterns even with magnets or convergence yoke rings.

If you don't have such patterns, it may be a degaussing circuit fault. It often fails down about thermistor terminals soldering. You should check if this circuit works properly. Be careful because Thermistor is hot mostly. It is always close the relay and connects to degaussing coil behind the screen.

Hope this help.

Regards

John_H

In the Sony sets, the purity magnets should be very well glued in to place.
Going from experience, the shadowmask in the CRT is probably damaged. These
sets are so sensitive, that a small drop can damage the shadow mask.

--

JANA
_____


"Tim" wrote in message
...
This one was dropped on the bottom left corner by the looks of the
cracks in the case. Now it has bad purity down the left side, and the
bottom right corner. I have found some info on the net here;

http://videotech.lesterville.com/sony.htm

I thought I would check here to see if there are any alternatives to
trying magnets etc to get the purity back. I seem to recall that the
rings on the neck of the CRT used to be used for purity too, but these
ones have not moved.

Thanks,

- Tim -

In article ,
says...
This one was dropped on the bottom left corner by the looks of the
cracks in the case. Now it has bad purity down the left side, and the
bottom right corner. I have found some info on the net here;

http://videotech.lesterville.com/sony.htm

I thought I would check here to see if there are any alternatives to
trying magnets etc to get the purity back. I seem to recall that the
rings on the neck of the CRT used to be used for purity too, but these
ones have not moved.

Thanks,

- Tim -

OK I have the purity fixed up perfectly now. I need to adjust the
rotation (tilt) of the pic tho, it is off by about 3/8". Does this set
have that adjustment in a service menu? I would need to know how to
activate that menu. I know I could open the set up again and adjust the
yoke manually, but I like to try the electronic tilt if possible.

Thanks,

- Tim -

Did you try to degauss the tube (a power cycle) after placing the
magnets?
Most of the times it will cancel their effect. On a similar problem
the only fix I found was to unplug the degausser once the CRT was left
properly magnetized and installed at its definitive place. A big
speaker magnet works pretty well at magnetizing CRTs.

Tim wrote:
In article ,
says...
This one was dropped on the bottom left corner by the looks of the
cracks in the case. Now it has bad purity down the left side, and the
bottom right corner. I have found some info on the net here;

http://videotech.lesterville.com/sony.htm

I thought I would check here to see if there are any alternatives to
trying magnets etc to get the purity back. I seem to recall that the
rings on the neck of the CRT used to be used for purity too, but these
ones have not moved.

Thanks,

- Tim -

OK I have the purity fixed up perfectly now. I need to adjust the
rotation (tilt) of the pic tho, it is off by about 3/8". Does this set
have that adjustment in a service menu? I would need to know how to
activate that menu. I know I could open the set up again and adjust the
yoke manually, but I like to try the electronic tilt if possible.

Thanks,

- Tim -

The set has been cycled many times since I placed the magnets on the
back bell of the tube. I did get some Silicon II to attach them with
tho, as I decided the double sided tape may let go after a bit. It still
looks great, just tilted now.

It was my understanding that trying to demagnetize the CRT is not
advisable because it will destroy the conditioning of the tube and it
will never return to proper purity again. And it really has come back
nicely, so I don't see the need to try and manually degauss the CRT.

In article . com,
says...
Did you try to degauss the tube (a power cycle) after placing the
magnets?
Most of the times it will cancel their effect. On a similar problem
the only fix I found was to unplug the degausser once the CRT was left
properly magnetized and installed at its definitive place. A big
speaker magnet works pretty well at magnetizing CRTs.

Tim wrote:
In article ,
says...
This one was dropped on the bottom left corner by the looks of the
cracks in the case. Now it has bad purity down the left side, and the
bottom right corner. I have found some info on the net here;

http://videotech.lesterville.com/sony.htm

I thought I would check here to see if there are any alternatives to
trying magnets etc to get the purity back. I seem to recall that the
rings on the neck of the CRT used to be used for purity too, but these
ones have not moved.

Thanks,

- Tim -

OK I have the purity fixed up perfectly now. I need to adjust the
rotation (tilt) of the pic tho, it is off by about 3/8". Does this set
have that adjustment in a service menu? I would need to know how to
activate that menu. I know I could open the set up again and adjust the
yoke manually, but I like to try the electronic tilt if possible.

Thanks,

- Tim -