MBox Pro Rear Input Jack Problem - Won't work unless the plug is pulled out a bit

[RickT]

I have an MBox Pro unit that was working fine until just recently when I could no longer get any sound out of the rear 1/4" input jacks. Today I found out that if I pull the cable part way out of the rear jack I get signal. It's never done this before. The front jacks work fine when the cables are pushed in all the way. Anyone ever heard of this problem before? I'm at a complete loss here

Thanks,

Rick

[zedhed]

Sounds like it might be a dry/cracked solder joint either inside the MBox or the cable itself.

[RickT]

I would like to agree with that except all four inputs in the back won't work unless the cable is pulled out a bit. It can't be the cable either. I've tried two others and they do the same thing and all of the cables work properly when plugged into the 1 and 2 inputs on the front of the MBox.

[zedhed]

Is it still under warranty? sounds to me like you're going to have to get someone to look at the unit.

[RickT]

Yeah, it's only 4 months old

[zedhed]

Well then, I would get it checked out while it's still covered by warranty.

[Bill Denton]

Are you using a Tip/Sleeve cable, like a guitar cable, or are you using a Tip/Ring/Sleeve pro audio cable?

I believe the rear inputs are balanced, and require a Tip/Ring/Sleeve pro audio cable.

[RickT]

Hey Bill, I'm just using a regular guitar cable. I'll go dig in my big box'o cables to see if I can find a Tip/Ring/Sleeve cable and see if that works. Thanks.

[RickT]

Well that didn't work either. I also don't see any mention of the ring sleeve type cable required for the back in the Mbox Pro's owners manual. There is however a toggle button on the front to switch from the front to back inputs. They don't do anything though.

I know the rear inputs worked fine before when I first bought the unit so I'm sitting on hold (30 minutes now) for an RA#.

[shai_shaashua]

Hi Rick,
Not sure if you are still dealing with this but anyway:
I just found out that on my Mbox Pro the wiring is wrong. as far as the mic/line and the front/rare buttons are concern, 1 controls 3, 2 controls 4, 3 controls 1 and 4 controls 2. Try playing around with these buttons. For example, to get a signal from line input 1 (1/4") the mic/line button on channel 3 needs to be engaged.


Hope it helps