Mesa Boogie Mark V Effects Loop huge volume drop

[CorrosiveMatter]

Sorry for the dumb question but my google foo is failing me in finding the issue.

I got a Mark V 90 a few weeks ago and set it up with an ISP Decimator in the loop and in front along with a boost pedal in the front (behind the gate) and everything was working as expected.

The other day I was moving stuff around in my office and I unplugged everything and rolled the amp/cab on casters across the room and plugged everything in again.

Now if the loop is engaged the volume has dropped by ~80% or more?

I don't think any settings changed during the move, but I also can't find a setting that would cause that?

Any guess what could be the problem?

Thank you in advance.

 

[DrewJD82]

I wanna say I’ve had more issues with Boogie loops than any other amp. I can’t speculate on this issue, but last week when plugging a delay pedal into my Electra Dyne I noticed a pretty decent volume drop and know I dealt with it on one or two of the Dual Recs I had as well.

 

[Frodebro]

Could be one of the loop jacks is dirty and not making a good connection, a Q-Tip soaked in isopropyl might be worth trying.

 

[CorrosiveMatter]

Even with nothing in the loop if it’s turned on I see the drop.

 

[DrewJD82]

Even with nothing in the loop if it’s turned on I see the drop.

You try fucking with the Send level or flipping the loop Bypass/Active switch just in case it got stuck in a weird in-between spot or something?

 

[Frodebro]

Even with nothing in the loop if it’s turned on I see the drop.

The loop uses shorting jacks to jump the send to the return if there is nothing plugged in. If they are dirty, bad things happen. Like volume drops and/or signal cutting out.

 

[CorrosiveMatter]

Thank you all, I just got a few minutes to mess with it and I figured out that I just have moved the loop mix to almost zero somehow... anyway all I good again.