ah, so someone set a minimum floor for the volume on your radio. If you have access to the CPS you can fix that
[edit] I forgot my product lines, and I don't remember if that was an option in the 1250 CPS.
Basically what I was saying was you can set a minimum volume that it can't be turned down below, and if that was set on the unit...that's as low as you can go. If it's above 0, you will always get something.
I'll fire up Lucille and see if I have a 1250 codeplug in the ol' gal.
if it's not, the 1250 heads come apart very easily and you can just unplug the internal speaker.