Jorge, I have uploaded the service manual to the members area. Here is a link to that page: http://www.tech-assist.org/secure/tip/main.htm Bob Waterman, CET® #RI-28 Master Technician License #9109 Service Manager / Parts Manager Gemini Computer, TV, & Security Alarms (508)695-7302 (508)695-7769 FAX geminitv@xxxxxxxxxxxxxxxx geminitv@xxxxxxx www.geminicomputertvsecurityalarms.com ----- Original Message ----- From: "Jorge Camboni" <geo@xxxxxxxxxxxxx> To: <techassist@xxxxxxxxxxxxx> Sent: Wednesday, June 11, 2003 8:34 PM Subject: [TechAssist] SONY KV35S66 CHASSIS AA-2D need print > > > > > > Hi techs. I'v been struggling with this (exceptionally) heavy > Sony KV35S66 set at the customer's home. > apparently, there is a problem with the vertical output. The output > IC is a TDA8172 and it is fed by +15 -15 volts originated in separate > flyback secondary windings. The PROBLEM ITSELF IT IS THAT > THERE IS NO PIC, NO RASTER unless you advance the G2 control, > the voltage on the 3 colour cathodes being over 200v (no video drive at all)= > .. > but when you advance the G2, the picture is a milky rainbow pattern > just like the old magnavoxes with one of the vertical psupplies bad, > because there is a 9VOLTS DC BIAS across the vert. yoke (there's > actually no vertical deflection, just a strong dc bias on the yoke) > and the set is protecting itself cutting any video output. ... > Well, I changed the tda8172 first.. no luck, then rechecked > both power supplies and they are somewhat asymetrical, the > positive being 11.6v and the negative 16.5v, that is quite a difference > but resistor, diode and caps are just fine on both, and unless on of > the flyback windings is bad, IT SEEMS THAT THE POSITIVE > POWER SUPPLY IS BEING DRAINED MORE HEAVILY, hence > the voltage difference. I checked all I could at the customer's location > and in this case I am unable to bring it to the workshop. I suspect the= > jungle > IC but I wont=B4t spend that money unless I am pretty sure of it. Need the > schematic to go deeper into matters, but I had to give him a rather low > estimate in order to do the job (big mistake) > If anybody could help with a print, or a clue on this case, I' d appreciate= > it > very much > > TIA Jorge > > Jorge Camboni, GY Electronics, Richardson, TX > > **************************************************************************** * > The Tech Address Book: > http://www.tech-assist.org/secure/tip/contact.html > Add a Repair Tip Here, or Change/Remove your Email Address: > http://www.tech-assist.org/secure/tip/main.htm > Lost Password: > http://www.tech-assist.org and select "Lost your Login Info?". > Email Archives: > //www.freelists.org/archives/techassist/ > ***************************************************************************** The Tech Address Book: http://www.tech-assist.org/secure/tip/contact.html Add a Repair Tip Here, or Change/Remove your Email Address: http://www.tech-assist.org/secure/tip/main.htm Lost Password: http://www.tech-assist.org and select "Lost your Login Info?". Email Archives: //www.freelists.org/archives/techassist/