Bassblaster
Super Member
I decided to pull out the Sansui A-1100 then been sitting on my shelf for over a year.
This model uses the STK3102II for the driver. whats going on it the right channel works perfectly no issues at all. Left channel is intermittently VERY distorted or doesn't work at all. I sat down with the scope and found the left channel is oscillating between 60 and 85ish kHz. i tested the input pins of the STK driver and the oscillation is on the left input so the issue has to be before the driver. when i tap the F-4773 control board (page 6 in the service manual) with a screw driver the signal cuts out, gets softer and louder, most likely a bad solder joint somewhere.
SERVICE MANUAL - https://www.hifiengine.com/manual_library/sansui/a-1100.shtml
STK3102II DATESHEET - http://pdf.datasheetcatalog.com/datasheet/sanyo/STK3122.pdf
1kHz tone - pin 15 on the STK
1kHz tone - pin 1 on STK
no signal, pin 1 on STK
another no signal, pin 1 on STK
This model uses the STK3102II for the driver. whats going on it the right channel works perfectly no issues at all. Left channel is intermittently VERY distorted or doesn't work at all. I sat down with the scope and found the left channel is oscillating between 60 and 85ish kHz. i tested the input pins of the STK driver and the oscillation is on the left input so the issue has to be before the driver. when i tap the F-4773 control board (page 6 in the service manual) with a screw driver the signal cuts out, gets softer and louder, most likely a bad solder joint somewhere.
SERVICE MANUAL - https://www.hifiengine.com/manual_library/sansui/a-1100.shtml
STK3102II DATESHEET - http://pdf.datasheetcatalog.com/datasheet/sanyo/STK3122.pdf
1kHz tone - pin 15 on the STK
1kHz tone - pin 1 on STK
no signal, pin 1 on STK
another no signal, pin 1 on STK