Riddled TV Repair Forum

DonL · Guest

I suspect either the fly ot the CRT might be bad. At plugg in there is a "arcing" sound from under the Flyback anode "cup" to the CRT. The Fly rings with 8 rings on pin 10 so that should be good but could there still be a short in the fly? Or is this set telling me the CRT is shorted? The HOT is good and all componants in the horz and vert. I just did one of these sets and the fly & hot were both out, does this fly have a rep for being bad? Any help is appreciated.
Don

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DWayne · Guest

Remove the anode lead from the CRT and make sure it is isolated so that it doesn't arc to anything. If high voltage comes up and the set stays on with the anode loose you have a bad CRT.

DavidM · Guest

Don , if I understand rite , it's archin' at the CRT anode cup ? If so ,
remove the cup and clean with the likes of windex or alcahol , ( PS ,
discharge crt first ) he,he,. AS if you didn't know . With our humidity here
, it's sometimes a problem

Don · Guest

Ok we did that and the HV still did not come up and stay up, so I ordered a flyback, now the hiss under the HV anode is gone but now it's a spark & a POP! It just so happens that another set the same RCA came in and was fixed, it also had a bad fly, so just to see if it would work we switched boards, and this board with the new fly does not power up the CRT, but no spark or pop. It seems to pulse, HV starts to come up but shuts down then starts to come up again & so on.
Anyone ever see this?
Don

DonL · Guest

Ok, Im still wrestling with this one, here's a recap
It was dead, I found CL12 burned and the trace dammaged that connects to the cathode of DL03 which tests good out of circuit, the HOT also tested good. I replaced the cap and hardwired the trace, the set would start up but there was a "sizzle" under the anode "cup" to the CRT, I suspected a shorted CRT but another ATC113CA1 came in so according to the boss I put this board in that set and it would not power that CRT up either.
The fly rings up good but we replaced it anyway, now with the new fly instead of a sizzle at the HV anode there is a spark and a POP!
What am I missing? And would anyone have the print?
Don

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John · Guest

Don, Hear are some tips on the ATC113. I don;t know if this will get you
going but its a shot in the dark.
Check to see if this model has the following parts. May not pertain to you
chassis
check TP20, Also there a 1 meg resistor that can open and cause no startup
Replace all the active components in the primary, the opto TP22, the
TP23voltae reference ic, and any transistor direct coupled to the opto. in
the secondary. Also resistors touching the power tranformer, base, gate, and
emitter source.

Also check for conductive glue under TL092 .

Good Luck . Those can give a headache real quick.

John

DonL · Guest

Thank you John, I will check all that someone else sent me the print so I hope with all that I can find this problem, the print helps with the voltage test points.
Don