Randy, I wish mine was the easy...33v zener still blowing and no cracks.. For yours, suspected a damaged micro. Jeff -- Intrepid Video TV/VCR Repair 263 S Front St, Steelton PA 17113 717-939-7708; (F) 717-564-4952 www.intrepid-video.com www.tech-repair.net ----- Original Message ----- From: "Randy Evans" <tvsvc2000@xxxxxxxxx> To: <techassist@xxxxxxxxxxxxx> Sent: Tuesday, September 21, 2004 11:52 PM Subject: [TechAssist] Re: Symphonic SC313C Combo Service Manual need explanation ? Hi Jerry: This one uses a PC817 Cpto-Coupler. The PCB was cracked in this area, where the screw fastens the PCB to the plastic frame. I did find cracked solder on Q604 Emitter too, which is in the same vicinity as the Opto-Coupler. Thanks for the help, as always ! Randy J. Evans VCR SERVICE Delta, Ohio 43515 J Silverman <greentron@xxxxxxx> wrote: If that set has a 431 reference IC for feedback in the secondary, check it carefully for cracked solder. As I recall, the IC was over the support frame and the bumping would crack the solder. Saw the same problem in three similar models. Jerry Silverman Greentron Inc 4 Newland Ave Greenville SC 29609 Fax/Phone 864 232 3889 mail to: greentron@xxxxxxx ----- Original Message ----- From: "Randy Evans" To: Sent: Wednesday, September 08, 2004 10:09 PM Subject: [TechAssist] Re: Symphonic SC313C Combo Service Manual need explanation ? > Hi John: > > Thanks for the response ! > > I don't have a problem with the T601 Transformer on this SC313C, > but I do have D615 (33v Zener) shorting out at random time intervals, and I can't > locate any bad parts that might be causing it to short, although I suspect a > crack in the PCB somewhere. > > If you look at a manual for other Funai/Symphonic models such as the SC3809, the power supply > test procedure instructs you to attach the scope probe to a pin that doesn't > exist on the transformer..... (such as pin 16, and the transformer only has say 14 pins) > so I guess the author made mistakes. > > Thanks for the help. I appreciate it very much ! > > Randy J. Evans > VCR SERVICE > Delta, Ohio 43515 > > John at Main TV wrote: > SC313C manual should be the correct manual. The transformer should have > pins numbered 1 thru 16 (there is no pin 3), the secondary pins are 11 thru > 16 with negative of scope (ground) to 12 and positive to 16. That is a > strange connection since 12 is not ground but then the waveform is strange > also. Are you saying your set does not have 15 pins on the transformer? > What is the problem with the set, does it work but makes a squeal from the > power supply? John. > John Mielke > Main TV > 636 main St. > Longmont, Co > phone 303 776 6955 > fax 303 776 0792 > maintv2004@xxxxxxxxxxx > ----- Original Message ----- > From: "Randy Evans" > To: > Sent: Wednesday, September 08, 2004 10:45 AM > Subject: [TechAssist] Symphonic SC313 Combo Service Manual need explanation > ? > > > In the Power Supply Troubleshooting sections of their Service Manuals, > they tell you to connect your Scope Probes to two terminals of T601, the > Switching Transformer. In almost every Service Manual, they tell you to > connect it to "Pins that don't even exist" on the transformer. > > What I need to know is: What Winding are the talking about? > > Positive Probe to ?? Negative Probe to ?? > > > > I Copied and Pasted an example from a Symphonic SC313 manual below, > > although it is in their other combo Service Manuals as well. > > > > Thanks, > > Randy J. Evans > > VCR SERVICE > > Delta, Ohio 43515 > > tvsvc2000@xxxxxxxxx > > > > > > 13" COLOR TV/VCR COMBINATION > > > > SC313C 6313CC EWC1302 > > > > Page 1-8-15 > > > > Power Supply Trouble Shooting Guide > > --------------------------------------- > > The transformer of the power > > supply makes a higher sound > > or the oscillation wave form is > > abnormal. > > (E.g. intermittent oscillation) > > Connect the positive probe of > > oscilloscope to the pin 16 of > > T601, then connect the negative > > probe to the pin 12. Observe the > > waveform and check to see if > > the waveform is out of limit of > > value shown in Fig.1. > > --------------------------- > > > > Voltage approx. 5Vp-p > > > > > > > > --------------------------------- > > Do you Yahoo!? > > New and Improved Yahoo! 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