I recently had an HM Strat re-wired at a shop.

Something weird about the Volume knob, it doesn't cut the sound all the way. It lowers the volume slightly, but acts more like a tone control.

I play tested it at the shop, and honestly don't recall encountering this. But I had it out to play around on it, and I noticed it then.

Is there an easy way to troubleshoot this problem, or has anyone else seen this, and might know of a common cause for this issue? I guess I can take it back, but would rather just fix it myself if it's something simple.

It's not the end of the world for now, because I have a volume pedal, but it would be nice to have the normal function of the volume knob on this guitar.

The volume pot was replaced when it was re-wired, and I looked in the cavity and don't see any loose wires.

Problem with the wiring , some mistake I think , or wrong pot . Is the work is warranty ?
Can you send us picture of the wiring ?

Volume knob only reduces the volume part way means the third terminal on the volume pot isn't grounded. The terminal may be bent over to touch the pot case and there may be a blob of solder on it so that it looks like it's wired correctly, but a cold solder joint can look perfectly good and yet be non-conductive. Cold solder joints can work at first and then suddenly fail, so the volume control might have been working properly at the shop.

Or the tech might have just screwed up and forgot to bend the terminal over and solder it.

Ok, I'll have to double check that ground when I get home from my root canal this afternoon.

That actually might explain one other kind of subtle issue I've been having with this guitar as well. Hopefully it's a two birds situation.