Hi all,
I have a moderate hum (probably mains ac Hz) on the right channel of my 9990, and it's too loud to live with.
I have tried a new 1000uF cap across the supply because i cant work out how to get to the smoothing capacitor that i presume is on the main board (the PSU board has no cap). -it didn't help
There is no hum with radio, only the line-in (when the tape player is set to record). It is here i think i am getting closer to the problem, because playing the tape (with very perished belts) there is a much louder hum(and/or oscillattion,approx8Hz). but 'recording' from the radio there is no hum, so now i'm confused and stuck
There is no hum with batteries.
using the light button changes the hum a little.
and it does increase when turning up the volume, same with headphones.
Any help or pointers would be very much apreciated as it's getting beyond me and my tools, and i really like this one.
I have a moderate hum (probably mains ac Hz) on the right channel of my 9990, and it's too loud to live with.
I have tried a new 1000uF cap across the supply because i cant work out how to get to the smoothing capacitor that i presume is on the main board (the PSU board has no cap). -it didn't help
There is no hum with radio, only the line-in (when the tape player is set to record). It is here i think i am getting closer to the problem, because playing the tape (with very perished belts) there is a much louder hum(and/or oscillattion,approx8Hz). but 'recording' from the radio there is no hum, so now i'm confused and stuck
There is no hum with batteries.
using the light button changes the hum a little.
and it does increase when turning up the volume, same with headphones.
Any help or pointers would be very much apreciated as it's getting beyond me and my tools, and i really like this one.