I think I found the problem. Disconnecting J1903 from the audio board and the set fires up fine. Found U1902 shorted 1, 4.(TDA2052) Gonna pick one of these up tomorrow and hope for the best.. Many, many of you sent me troubleshooting guides, advice and Mr. Larkman suggested the audio board in the beginning. I've never had a problem on the audio board on this chassis and thought I was disconnecting it all this time(the two connectors near the Audio jacks). Thanks to all of you..way too many to mention. Here's what I found prior to going to the audio jacks..I have no idea how this all happened..some coincidence. 1. First, the HV block was arcing at the Flyback lead. 2. Planned to replace the power supply parts, since this set had the original parts...replaced them all. 3. Replaced flyback..old one rang good, but had a pin hole 18 months ago I covered with HV putty. 4. Replaced CR4118..tested fine. 5. Replaced the power supply parts again, assuming I had a bad part. 6. After the last bout of suggestions, found the resonator area looked a little damp. Unsoldering, I could smell it...replaced resonator and the cap beside it. 7. Removed CR4119, CR4120(I think)..sit right below the power supply transformer, beside each other. These two had definite leakage. 8. Now, all the wave forms in the power supply looked fine and micro voltages were fine. This is when I saw where the real audio board was. 9. Removed both connectors and set fired up fine. Replaced the one(leaving J1903 off) and set still fired up. 10. Checked both IC on the heat sink and found one shorted 1 and 4..comparing to the other one I knew this wasn't right. I'm surprised a bad HV block lead me to the audio board, but I hope to finish this set tomorrow morning and deliver to a patiently waiting customer. I think I made about $2. per hour on this one.
Jeff Dougherty Intrepid Video TV/VCR 263 S Front St Steelton PA 17113 fax...717-564-4952 www.intrepid-video.com www.tech-repair.net ----- Original Message ----- From: "Intrepid Video Support" <[EMAIL PROTECTED]> To: "Tech List" <[EMAIL PROTECTED]> Sent: Friday, March 05, 2004 11:25 AM Subject: [Techs] TA RCA PTK169(CTC169PAAS) Model P46770CKLG1 CTC169PAAS CL4413. This set looks like one of the first 169's..I'm embarrassed to post a question on this set being so familiar..but I've checked all I can think of. At customer's house, found HV arcing at splitter. I assumed bad splitter..so replaced. Then, set would fire three times, remove anode lead and fires once and shuts down. Replaced flyback, same thing. Replaced HOT, regulated supply (U4101, Q4101, all caps(4) checked all resistors and replace 3v zener(measures -1.5 on anode and 1.5 on cathode in run) HV comes up to about 35k. HOT coll is 147 in standby, drops to 143 in run. B+ at fly about the same. Q4101 C=174 in stand by, 157 in run. Disconnecting the HV board(on the HOT heat sink) makes no difference. With the anode connected to the HV block, some times the set tried to start three or four times, other times only once.(Disconnected, only once) First guess was another bad fly, but both actually ring good on my Sencore VA48. I started back tracking in case I got bad parts for regulated circuit, but I get the same symptoms. All parts are OEM except U4101(which I now have the original part in unit). I have the Fix finder for this chassis and went down through every thing. Has anyone seen these symptoms? Thank you Jeff Dougherty Intrepid Video TV/VCR _______________________________________________ Tech Repair CD...order your just $49.00 plus shipping...One year of updates free. www.intrepid-video.com www.tech-repair.net Techs mailing list [EMAIL PROTECTED] http://intrepid-video.com/mailman/listinfo/techs_intrepid-video.com
