Thanks for posting this. Saved me the time digging it out of the files at work. Steve at HQ originally posted this. I am glad that this will save others time & fustration. We were going nuts till we figured it all out. Frank Dr. Digital ----- Original Message ----- From: "Intrepid Video Support" <[EMAIL PROTECTED]> To: "ELECTRONICS PROFESSIONALS LIST" <[EMAIL PROTECTED]> Sent: Wednesday, February 25, 2004 4:16 AM Subject: Re: [Techs] RCA P46770CK/ PTV169PA///FBT question.//
> Joe, > Thanks very much,....that's what I was looking for... > > 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: "Joe Tech2004" <[EMAIL PROTECTED]> > To: "ELECTRONICS PROFESSIONALS LIST" <[EMAIL PROTECTED]> > Sent: Wednesday, February 25, 2004 12:45 AM > Subject: Re: [Techs] RCA P46770CK/ PTV169PA///FBT question.// > > > Jeff, > This is what I have, it's originally from you hope you gave yourself > good advise...:) GL "joe" > ================================== > RCA P46770CK/ PTV169PA FBT > I suggest you read the following post before proceeding to see if this > is applicable to your situation. Please let us know if it is so we can > gather this information and forward it to the appropriate personnel: We > ordered a 232191 IHVT from Union Electronics. This was for a PTK169. The > first one we received failed to work. Many hours troubleshooting time > spent and unneeded replacement parts were installed determining > something was wrong with the new flyback. (Holly at Union again verified > the part number was correct.) Another was ordered again from Union. > Again many hours of time was spent determining that this part was also > bad. This was confirmed when a known good flyback from a working set was > substituted temporarily and the set fired up and worked beautifully. A > third transformer was ordered, this time from Andrews. (Willy at Andrews > also verified we were ordering the correct part). The part from Andrews > arrived and worked just fine. All 5 transformers, the original, the one > from the working set that was used as a substitute, and all three new > flybacks had the same part number on the flyback, 2G25018 and TCE > 30.0KV. All three new flybacks had the part number 232191 on the boxes. > During the course of checking the transformers against one another we > discovered that apparently the 2 from Union were MIS-LABELED AT THE > FACTORY! They appear identical on the outside with one exception: The > two original FB's and the 3rd successful FB all had a green ink splotch > about 1/2 to 3/4 inch in diameter on them, whereas the two that did not > work had no such splotch. I don't know how significant that is. We > determined that these transformers were made to be used in the direct > view chassis and were MIS-LABELED AT THE FACTORY. According to the tests > we performed here, it has to do with the way pin 6 is connected on the > direct view VS the PTV-- In the Direct View CTC169, pin 6 is the low end > of the Anode winding. In the Projection PTK169, the black wire (also > present on the Direct View flyback) is the low end of the Anode winding > and is connected to a circuit that looks like it monitors beam current > and limits peak brightness. Symptoms of the wrong FB in the Proj set: > Standby is just fine. Hit PWR: Momentary Horiz drive. 200V line only > goes up to about 100 or 120V and the 26V line goes up to about 36V, as > measured on a 'scope. If you short pin 4 of T4101 (Run regulator > feedback) to hot ground as per the official Troubleshooting manual, > R4762 (430 ohms 1W) on the HV Reg PCB (mounted on the H.O.T. heatsink) > blows the magic smoke. This HV Reg PCB is not present in the Direct View > set. How to test before installing the FB to make sure that you have the > correct one: Using the Sencore VA48, Horiz SCR output, connect ground to > pin 1 and drive to pin 11. Use your scope to adjust to 10V positive peak > pulse drive. Here's the key to the test: If you measure the anode > voltage using the wrong pin as ground/common, the voltage is too low. > The exact voltage is very sensitive to the drive voltage, so comparison > is the key. Proj FB using black wire as common on 10M DMM: 220 to > 230Vdc. Proj FB using pin 6 as common on 10M DMM: 150 to 160Vdc Direct > View FB using black wire as common on 10M DMM: 150 to 160Vdc Direct View > FB using pin 6 as common on 10M DMM: 220 to 230Vdc I'm sure you see the > pattern. :'/ A cross check of the Thomson PTK169 service manual on CD vs > our paper Thomson CTC169 is inconclusive as the schematic of the PTK169 > FB circuit labels the low end of the anode winding as pin 6. The PTK169 > service manual lists the replacement part as 232191. > ================================== > [EMAIL PROTECTED] From: [EMAIL PROTECTED] > (Intrepid Video Support) Date: Tue, Feb 24, 2004, 11:07pm To: > [EMAIL PROTECTED] (Tech List) Subject: [Techs] RCA P46770CK/ > PTV169PA///FBT question.// Reply to: [EMAIL PROTECTED] > (ELECTRONICS PROFESSIONALS LIST) > A little over a year ago there was a discussion regarding the flyback > for this projections set. I had ordered 232191 three times and none > worked. > I come to discover, these apparently were for direct view sets, not > Projos.. The unit I had at the time, I ended up using HV putty to seal > the hole. I have a service call on this unit about 15 months, I think > the HV leaked through my repair. Has anyone had success with this part > number lately using it on a projection unit.. I am familiar with the > notes that come with this part, but that is not an issue.. I believe > someone mentioned our friend in Mexico had been mislabeling these, or > something to that effect... > > Thank you. > 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 > ______________________________________________ > 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 > > Joes....Electronics > (Joe:Tech/2004) > [EMAIL PROTECTED] > Fax::509-479-2283 > > > _______________________________________________ > 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 > > > > > _______________________________________________ > 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 _______________________________________________ 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
