[Charlie]

After my experience with conductivity between isolated PCB traces, I went to the parts house to get some new cleaner spray and discuss my issue with the guy that runs the place.

I described in detail what happened and the man was very surprised of the results I ended up with. The man pointed out that the spray can be used on IC's. Like myself, he figured if it can be used on IC's, it can be used on tube sockets.

I picked out a can of MG Chemicals Electrosolve Contact Cleaner- Zero Residue, Non-Conductive. This stuff says it cleans and degreases all the normal stuff... including micro-processors, tuners, and printed circuits.

Now, things seem to be getting better. A couple of days ago, I would turn on the set, and it would take about 5 or 6 minutes for the picture to straighten out. Everytime I've turned it on since then, it takes a little less time for it to make a good picture. This morning, I turned it on and it straightened out after only a minute.

The set is producing a pretty good picture, however there are a few flaws. Sometimes when I turn it on, the screen is black with no raster (but has HV) and I've found that changing the channel makes the picture come on. At first, I thought it was something loose, but if I tried hitting the set or tapping various locations, that doesn't help. Only changing the channel helps. I've also noted that when the raster is missing, the 3rd IF tube is glowing twice as bright as it should. As soon as I change the channel and the raster comes on, the IF tube glow goes back to normal. I'll try changing that tube and see if it helps.

I'm having difficulty getting the verticle height and linearity set correctly. The top of the picture is a little stretched out and makes a circle look like an egg.

In a black and white thread, I mentioned having a light verticle line in the left side of the screen on my b&w sets... and that I hadn't seen it on a color set. Seems I shouldn't have made that comment, because now I have the same line in this color set. My horz drive is set correctly. Last night, I read in a book that changing the damper tube will sometimes correct this, so I'll try that and see what I get.

I'm noticing that the bottom part of the picture does not focus as well as the top. Focus voltage is correct.

I'm thinking it's possible that the focus, light verticle line, and vert height/linearity problems are all related... and possibly the culprit could be the flyback. The flyback is running cool... no hot spots. I had changed this flyback in the beginning, however, it was pulled from another chassis. It's a replacement part... not an original RCA flyback.

On the positive side, the color and contrast is really good.

It appears that this set was REALLY worn out when I got it!