hi guys im trying to repair my active subwoofer its an expensive piece of kit. so id rather fix it than bin it. its a monitor audio vw8 active sub its a push pull ab amplifier board, ive got the scematics here ill post below, ive already repaired this once before:
https://www.badcaps.net/forum/showthread.php?t=32471
this time as the title sudgests ive got 35 volts at the speaker terminal!,
im not smart enough to say whether this has an output thats capacitor coupled..
the speaker hums like 60hz or 120hz, theres no input and the volume doesnt change the sound atall. i unplugged the pre amp section and the hum doesnt stop.
transformer is centre tapped ground but it seems ok
outputs are tip35c/tip36c, they seem ok too
driver transistors seem ok
filter caps were replaced theyre ok
bridge rectifier is new also
shouldnt the protection relay prevent this?
What am i Missing? any help would greatly bee appreciated, thanks for reading guys
https://www.badcaps.net/forum/showthread.php?t=32471
this time as the title sudgests ive got 35 volts at the speaker terminal!,
im not smart enough to say whether this has an output thats capacitor coupled..
the speaker hums like 60hz or 120hz, theres no input and the volume doesnt change the sound atall. i unplugged the pre amp section and the hum doesnt stop.
transformer is centre tapped ground but it seems ok
outputs are tip35c/tip36c, they seem ok too
driver transistors seem ok
filter caps were replaced theyre ok
bridge rectifier is new also
shouldnt the protection relay prevent this?
What am i Missing? any help would greatly bee appreciated, thanks for reading guys
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