G 7500 owner

[charlesb313]

My G 7500 receiver has a burned resistor (R-57) on the F-2980 power supply/driver board. It is burned beyond recognition. I am trying to find the value so that I might replace it. I was able to get a copy of a G 7500 service manual, but the board lay-out on the schematic is diferent than mine. Almost like a newer or later version of the board. (same F-2980 # though) Even though the manual shows R-57 on the Board lay-out, it does not list it in the parts list so I have no idea of the value. Any help would be appreciated.

Thanks, Charlie

 

[SSBN 618]

I have the schematic that was included when I purchased my G-7500 way back in 1979. (98M1) <9237900> is printed in the lower right corner, it looks like the revision number. On board F-2980, resistor R-57 is showing a value of 1.5K.
PS I tried scanning so I could attach it but, even at 1200dpi the resistor values are not legible. If you need a paper copy, let me know.

 

[dr*audio]

Chances are, if the resistor is burned beyond recognition, there is something more serious wrong with the amp. The resistor you install will look like the one you replaced very shortly after turn - on. The resistors that usually go bad in the Sansui equipment are only slightly discolored, not burnt to a crisp. R57 is a 1.5K in the protection circuit. You should check TR19, the protection transistor, and the output and driver transistors as well. Additionally, if the outputs are bad, R43 and R49 are probably open as well. Also check the bias pot, VR03.