CRT Coolant Change Lens Removal Question

**helios007** · **06-15-09, 10:46 AM**

Hi,

This is my first post here, and I have to say thank you to all of the great advice here. I really appreciate all of the patience and insight that this forum has. I have already successfully replaced my IC chip to fix my convergence issue on my Phillips 55PP9363H/17B, and am in the process of changing the CRT Coolant.

I have the Blue CRT out, and have drained all of the old coolant (which was a nice yellow color). I am about to clean the lens and coolant chamber, but want to make sure that I am removing the correct parts. The instructions posted by lcaillo say "Remove the lens carefully by pulling the four mounting screws while holding the crt pointing up over a basin".

http://www.hometheatershack.com/foru...-problems.html

I just want to make sure that I am taking off the correct screws. I am assuming that I need to remove the 4 torque/star male screws on the lens rather than the 4 silver bolts with the springs. Is this correct?

Also - on another note. When I did the IC repair, even thought I carefully labeled all of the cables I must have missed one because the non-HD inputs (AV1, AV2, AV3) only show a magenta screen, but with audio. Anyone have an idea which cable I missed. I'm not sure of the protocol here - should this be under a different thread?

BTW - the photos posted by BrookeClarke were really helpful! Thanks for taking the time to post those.

Thanks,
Walt

**lcaillo** · **06-15-09, 11:22 PM**

Those are the correct screws.

Never ran into that problem with magenta, just make sure everything is plugged in completely.

**helios007** · **06-16-09, 09:23 AM**

Thanks for the quick reply. I appreciate all of your posts and responses, they have been really helpful. I'll be sure to post how it goes.

**helios007** · **06-17-09, 10:46 AM**

Ok - so the coolant change went mostly as expected. However there was an issue, and I don't know how big of a deal this is - so any insight would be appreciated.

When taking out the CRT from the TV, I accidentally moved the rings around the yolk. Fortuntately I had taken many photos before removal, in case something like this happened. I returned the rings to the position of the photos and powered up. The blue color is now amazing again, however the blue convergence is way, way off. Did moving those rings cause this? Is this something that can be adjusted? Just as a reminder, this project started off with replacing the IC chips, and before removing the CRT, the convergence was excellent.

Thanks,
Walt

**lcaillo** · **06-17-09, 10:59 AM**

The rings on the yoke are the positioning magnets for the CRT. You should be able to move them to get the center convergence to line back up. If the size of the image is not the same, you may need to adjust the position of the yoke on the neck, moving it forward or back. The coolant may also have a different density than before, so there may be some convergence touch up needed after you get the yoke position and magnets as close as you can.

**helios007** · **06-18-09, 04:44 PM**

Thanks Leonard for the help. I hope that my questions aren't too obvious.

I didn't have much time last night to make the adjustments, but what I found was that the highest rings on the yoke (furthest away from the tube - closest to the lens) make the most difference, but I couldn't quite pull it in to match. The lower rings (nearest the tube) didn't seem to make a much of difference. I can pull the convergence in around to the middle, but the upper right and lower left still are way off. Would adjusting the yoke forward/backward fix this?

Do you have a tried and true methodology for adjusting these magnets - or is it a trial and error type procedure?

Thanks,
Walt

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