Sansui 8080DB, Tuner problem

[hugo22]

Hi All,
Please advice, my lovely sansui has tuner problém. Tuner is generally not working, when select eiter FM or AM function ( by switch func. selector) both tuner analog indicators don´t " move" when tuning from 88 to 107MHz, also no speakers output.

Antenna connected
FM indicator lights
other inputs AUX, Phones, work perfectly
thanks for every piece of advice
M.

 

[DougBrewster]

Check the RF supply board F-2619 for 12V at pin #1. These boards fail often at the 270 ohm resistor solder joints due to heat..

 

[hugo22]

just have checked, measured against blac wire G
pin 1 = 0V
other voltage ( based on schematic diagram) 14V, 10.5V is not there. I measured 62V in both
only 5.8V is there.

 

[hugo22]

board re - soldered, of course

 

[DougBrewster]

so you have an open circuit at F-2619 where the 44V supply is connected through the 270 ohm resistors R01/R02 and into the regulating network. The 5.8V is OK because it comes from a separate supply to feed the FM Stereo lamp. Check the pcb traces around R01/R02 again. After that you need to test the three transistors and other components. Something is open circuit...

 

[hugo22]

Hi All, after replacent TR01 and TR02 at F-2619 Tuner works ( 12 volts at pin 1 is back).

Thanks a lot for your help.