With many of your help, I got the '71 RCA console TV going again. I believe in leaving well enough alone; however, the upper left and right quadrants of the screen get a weird red cloudy blotchy color when red is in the picture, e.g. a man or woman with red clothing, or the skyline, etc. It is not an intermittent problem or one that is random - it consistently does this in the same scenes on a DVD player or watching the news, etc.

I suspected the purity may be off (RED) but wasn't sure if it was just a convergence touch up issue. I've not yet hooked it up to a crosshatch generator because I've been hesitant to monkey with it more before I got your guys' advice. Verdict - purity or static/dynamic convergence or both?

Recap of recent work: New PW400 board (horizontal sweep), new SCR transistors, rebuilt video and chroma boards (bad components) and newly rebuilt tube installed.

Thanks!

I can think of two things right off the bat...You may need to degauss the CRT with a degausing coil (which would not be a bad idea anyways), or the yoke has moved slightly. Untighten the wing nuts and slide the yoke forward and observe. Did it get worse? Now slide it back a bit and see if your blotches dissappear. Hopefully you have a good size mirror to place in front of the set for your observations.

Sometimes you can adjust it for that "sweet spot". If this fails then Purity adjustment may be in order.

I second the possibility of purity issues. Would much MORE suspect that from a set that I've had all apart and have been working around the yoke at all.

You also coulda just moved the set maybe WHILE it was on?....or maybe it's onboard degausing isn't up to snuff. (thermistor, degausing coil itself, etc). I'm a bit rusty on these things since I not worked on a color set in at least a decade, but I would suspect you HAVE to deguass before you even look at purity.

I'm not thinking convergence...since if I remember correctly, it presents as colors not "lining up" on eachother....more than "wrong color"

Feel FREE to say I'm full of it though if I need to be set straight on this. I do currently have a small 6" Sanyo solid state set that is also showing red up top...and I have NOT looked at it yet. It has a manual degauss button that is obviously working, but I also have a red hue at the top of that screen. My first thought was purity when I saw that.

I'd hafta likely look around a bit to remember how to do purity. I remember it being "blank raster.....everything down but red.....Yoke back until you see a red area, move yoke magnets till this red area is in the center" (then of course put the yoke back with a crosshatch so it goes back straight).

Am I at least SOMEWHAT remembering this right? (It's from when I did this in high school years.....like 30 years ago)

My collection is mostly "micro" TV sets, so they tend to ONLY be B/W....or some newer LCD sets (I've NEVER heard of purity or convergence on an LCD set...and certainly not degaussing). I do have a couple 5"-6" color sets I've just not felt like "playing with" yet. I hafta someday get into that 6" Sanyo "combo" set and fix this same "red on top" thing....because that is one of the sets I actually turn on and watch often if the big 55" Samsung is on another source like the VGA (HTPC)

sounds like degauss needed to me also . maybe a magnet got near the screen and thrown it out ..
i used to fix these issues with a permanent magnet and pulled things straight again ..a bit of a red-neck approach but it worked for me

You can degauss with a soldering gun: turn on when you're at least 8 ft. from the set and approach slowly, move near screen slowly, back away 8 ft. before letting go of the trigger.

I once degaused an old GE set with a FISH TANK air pump. I would guess pretty much anything with a strong electromagnet would work. I was taught to "hit the switch" close to the set...and then move back slowly while moving your degausser in circles.

I thought ALL color sets have their own degauss? or was this just the later ones. I had never worked on a tube set extensively. I think maybe some of the sets we had at my high school TV shop were tube sets, but all I did was learn to use a tester, rejuvenator and to take out the tubes and test 'em. I've NEVER had to work on a tube set "for reals".