OK. Here goes. I'm hoping someone may be able to help me out. I am an electronics neophyte so be gentle. I know enough to get myself in trouble but that's about it.
The Problem
I have a Harman Kardon Subwoofer (model HKSUB-12). The sub is great and works fine except for one problem. I am unable to adjust the volume. It, for the most part, is at full volume no matter what level I set. The volume knob will work periodically through. It will sometimes go to the level for a brief period of time and then jump back up to full volume at will.
My lovely wife tells me to buy a new sub. I'd like to take a shot a trying to fix it first.
The Investigation
My "gut" tells me this is a volume control issue based on the subs behaviour. I think if I try replacing the volume control it might resolve the problem (this may be completely wrong but I think it is worth a shot).
I've managed to find the Service Manual for the sub and I've started to poke around.
The volume control sits on a circuit board.
This is the circuit board
The volume control is labelled VR201. The parts list is here show it as a Variable Res. 50KA
Here is Where I Need Help
In my simple way of thinking of things it should be as simple as getting this part and replacing it on the circuit board (I have tinkered with soldering many moons ago).
I don't know what exactly I should be getting or looking for. What would be a suitable replacement part? Like I stated above I'm willing to attempt this repair on my own but I'm not sure what to do next. A Google search of 50K Variable Resistors is a bit overwhelming.
Edit: I should add that I have tried contact Harman Kardon to see if I can get the part from them but no go. This sub is no longer manufactured.
Anyone have any advice?
More Info
Circuit Diagram
Block Diagram
Service Manual
Thanks
The Problem
I have a Harman Kardon Subwoofer (model HKSUB-12). The sub is great and works fine except for one problem. I am unable to adjust the volume. It, for the most part, is at full volume no matter what level I set. The volume knob will work periodically through. It will sometimes go to the level for a brief period of time and then jump back up to full volume at will.
My lovely wife tells me to buy a new sub. I'd like to take a shot a trying to fix it first.
The Investigation
My "gut" tells me this is a volume control issue based on the subs behaviour. I think if I try replacing the volume control it might resolve the problem (this may be completely wrong but I think it is worth a shot).
I've managed to find the Service Manual for the sub and I've started to poke around.
The volume control sits on a circuit board.
This is the circuit board
The volume control is labelled VR201. The parts list is here show it as a Variable Res. 50KA
Here is Where I Need Help
In my simple way of thinking of things it should be as simple as getting this part and replacing it on the circuit board (I have tinkered with soldering many moons ago).
I don't know what exactly I should be getting or looking for. What would be a suitable replacement part? Like I stated above I'm willing to attempt this repair on my own but I'm not sure what to do next. A Google search of 50K Variable Resistors is a bit overwhelming.
Edit: I should add that I have tried contact Harman Kardon to see if I can get the part from them but no go. This sub is no longer manufactured.
Anyone have any advice?
More Info
Circuit Diagram
Block Diagram
Service Manual
Thanks
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