RCA cd197 36inch color
 

Ok I have this RCA cd197 color and its from 1996 works great but they are known for flybacks every few years but for awhile now while watching the screen flickers bright and the images have a blue smear on them then it will be normal but does this at random so the question is that is there anyone that has had something similar to this problem. Maybe a bad cap on the neck board I really don't know but the set works great and I want to try and track down a cause and fix it. Any ideas would be great.

Intermittant H-K short in blue gun of CRT. :thumbsdn:

Is there a way to try to eliminate it without a crt tester for that tube. Or maybe modify a tester I have here to maybe clear the short. Or a separate heater source.

May not be CRT. You can tap the neck & see if it comes & goes
but you also shake the CRT board.
Most sets the filament comes off the FBT & one side goes to ground.
You have to lift it above ground & if its grounded in the FBT
out of luck. Also when you get a H-K short USUALLY the K goes
to 0 V & lights up bright the bad color then set goes into
shut down.

Another test is lift the blue K & one of the others. run jumpers to
swap the K's & see if the blue still acts up or it goes over to
the other color. Do it with a B&W pix to save confusion !!

Sears had a crap load of 19" Sanyos with Sylvania jugs shorting.
Cure was get the filament above ground & add a 1.5 meg & .001
cap but I dont remember where ! IIRC the resistor went from the bad K
to filament but dont remember where the cap went:no:

BTW someone used to make an isolation booster that worked on
the sweep freq. You would wire it for no boost.
Maybe Brian remembers ?

73 Zeno:smoke:
LFOD !

Well upon turning on it flickers bright then normal but when it gets bright the edges are blue and smeared and turning it on as the crt lights up there is a lot of blue then after a minute the blue calms down then flickers from time to time and other times it won't flicker. So I did think it may be a cap on the neck board and the fly is 2 years old or another cap in another area of the board. The set never went into shut down.

Timmy, going to need to know the chassis number. Most likely starts with "CTC-XXX",the x's meaning the three numbers also include any letters and numbers that follow. Zeno you isolate the fly winding from circuit ground that feeds the crt heater, the resistor feeds B+ to the heater to prevent any arching from happening. If heater winding feeds any other circuit then you need to add another winding that is not at ground. All the best,Tom.J

Ok the tag shows ctc197cd .

All these ills the last bunch of CRTs develop- I had a 36 Magnavox that would flicker & zone out after awhile, & a 36" Sony that also had a bunch of funky weirdness after it had a few years on it.... I NEVER have heard 1st or 2nd round of color crts pulling stuff like the latter day tooobs did- Had quality slipped THAT badly ? Part of the reason I got a 36" Sony was the Trinitrons HAD BEEN the Gold Standard for so long...It was almost painful to see..One gun-Usually the Red would crap out- & you may as well turn the sumbich off & go beat the cat, the wife, the dog, whatever.... Cause you wasn't gonna watch no more TV on IT for awhile...I dunno about the rest of youse guys, but I would have rather HAPPILY paid a little more dinero if I coulda bought a 36" CRT built to, what,1975 or so standards... Or whenever they started makin' them so cussedly CHEAP... I tell my "Civilian" friends that they about had HDTV color in 1954- & tell'/em to check out an early set that had been all properly set up by someone who knew what they were doing...Too bad they never really made "Milspec" color CRTs...

A quick easy way to isolate it is to disconnect the normal CRT heater path and run a loop or two of hookup wire around a convenient part of the FBT ferrite core, keeping it well away from the HV overwind, and connect this to the CRT filament. You can judge how many turns around the FBT by looking at the color of the CRT filament glow. If the fault doesn't return then you can safely assume it's an intermittent heater to cathode short on the blue gun. I've used this method many times to revive otherwise uneconomical set repairs. If the tube is faulty you've got nothing to lose. Sony Trinitrons were very prone to CRT H/C shorts. If the fault is still present then you've isolated the CRT.

- Sandy G.