> Recap" > This set has a great picture, but the sound would > go off in about 5 seconds. > List members were generous in providing > schematics. > One tech suggested opening up the DC sense line > to > see if that was the problem. > I unsoldered pin 16 of JS1900. > The audio stays on longer now, but still shuts > off. > There is a slight thump in the speakers at turn > on, > but nothing unusual at all when the sound > disappears. > I got out my trusty Radio Shack audio signal > tracer > and I have sound on pin 7 of U1901 and U1902 at > all > times. > This can be varied with the sets volume control > as > it should. > Pins 2 and 4 have the required +17 and -17. > Pin 3 shows -12.3 on the schematic. > there is -17 there at plug in. > That goes to -13 when sound is present, then goes > to app. -15 when the sound disappers. > The afore mentioned pin 16 JS1900 is still > unsoldered. > This might be a clue. > When I was testing the voltages the probe slopped > and I temporally shorted Pin 5 to 3 on U1901, and > the sound returned briefly. > I have to admit that I don't understand this > mute/DC sense circuit. > Anyone got any clues at this point? > TIA > Walter
===== Walter Wood Future Tech Home Center 2786 Hwy. 43 N. Lawrenceburg Tn. 38464 931-829-3337 Fax 931-829-4044 mailto:[EMAIL PROTECTED] _______________________________________________ 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
