Sony Trinitron color fading

[jt01]

There's something I've always wondered about relating to my history with Sony Trinitrons. I bought a 17 inch Trinitron in 1978 - it was great until the color started fading in the mid 80s. Replaced that in 1985, passing the 78 model on to friends, with whom it shortly faded completely to b+w. The 19 inch 1985 Trinitron set was fine until the early 90s, when again the color started fading. Replaced it in 1992 with a used 27 inch Sony, vintage 1989, I think. This lasted a bit longer and the color didn't fade, but I replaced it for other reasons in 1999 with a Panasonic. My question is - Trinitrons were excellent TV sets, but was there something about them that caused color fading after about 7 years? As you can see from the above, it happened to me twice. Sorry I don't have model numbers, etc. but they are all long gone.

[damen]

A lot of Sony's from that era developed issues with the board mounted trim pots. ACC one affected color saturation. Hue centering, horizontal hold and even the IF and RF agc controls would cause problems and don't forget the drive and pincushion ones. Usually a squirt of cleaner and rotating several times fixed them, but the long term repair was replacement.

[MadMan]

My 90s trinitron has had all sorts of problems. And just about every time, it was broken solder joints. That, and dirty card edge connectors.

[Electronic M]

If general color saturation fade to monochrome was the problem then it probably would have been a reasonably cheap fix at a repair shop.

Sonys were notorious for a different type of color fade, one of the 3 color electron guns would fade and you would start to loose red, green or blue leaving the whole picture (whether the show was monochrome or color) tinted some funny color....when that happened it meant the CRT was on it's o out... Cheaper to get a new set (or crank up the drive on the weak one and start saving) at that point.

[Popester]

Sony combined a AFT/Preset color with most of their ‘70’s tv up to late ‘80’s sets. They used a separate set of pots for color saturation and tint. With auto color on the main color and tint pots had a reduced amount of range. Often times the issues were fixed with cleaning all the pots. The sub color and tint range pots would get tarnished and show up as color intensity fading in and out or hue changes to it. Usually a good cleaning of pots and checking for board cold solder joints was all that was needed. Sony boards seldom had component failures but connections and cheap pots helped to add to the problems. CRT’s did seem to have limited life and it was usually red that went first.