On Jul 9, 1:57*am, "N_Cook" wrote:
wrote in message

...
On Jul 7, 9:11 pm, Don wrote:



I have a 25 year old Sony KV-20XBR TV that's been darn near perfect
over a quarter of a century! Amazing... last week, however, it
decided to die. Here are the symptoms: 1). Color was obviously off,
so I checked it with a color-dot-bar generator. It appears the Red is
gone, as the only bars seen are shades of blue and green, and 2).
Later, the picture slowly went to almost black -- you can make out
images, but vaguely.

Although I'm a tech (RF), I have no experience with TV
troubleshooting. I know the TV is obsolete, but it's in "as new"
condition (not a scratch), and I really hate to take it to the
recyclers. Any thoughts... do you think it might be in the red drive
circuit, focus circuit, the flyback, or the Trinitron CRT. If it's
the latter, cost-effective repair is out the window. I believe this
series of sets had a problem with cold solder joints. Although I
doubt this is the problem, I thought I'd just mention it.

Thanks,
Don

Do you have an oscilloscope??

and an isolation transformer for it *of course

Yes, I have a scope, and isolation transformer. I do not have a CRT
tester, but I've collected a fair amount of test equipment over the
years. I will attack this problem soon. Thanks.