Bartolini preamp query

[Olivetti17]

Hi all. 

I have just recently had a new set of pick ups and a bartolini preamp(active/passive) installed in my bass. I've noticed however, that the volume pot doesn't kick in, until at least 90%.. And also when switched to passive mode, the volume is almost completely lost. I've tried different trim pot settings, but still no improvement. I'm just asking if anyone has any ideas as to why. 

Thanks

 

[Hellzero]

IIRC, the volume pot is a 25 kOhms linear type, so not fantastic in passive mode.

 

My guess is that the pot is simply dead...