Help! FX loop not working on mark v!!

[Ben Gregory]

Hey ! How goes it?

My fx loop suddenly stopped working today when I turned the amp on. It worked the day before just fine. I turned it on and when I hit the fx button on the footswitch the amp sounded as if it is muted. I looked on the back of the amp, and the switch was on loop active and the loop :?: volume was near dead center, so I have no idea what is prohibiting it. I am using a MXR carbon copy and it was on when the fx loop on the footswitch was pressed. I am not sure what the problem is and I will continue to investigate. Any suggestions? Thanks!

 

[SteveO]

Check the effects return tube (V6). Swap it out with a good 12ax7 and see if that cures it.

 

[Anonymous]

also try running the pedal in front of the amp (just to make sure that the pedal is in working condition)

good luck

 

[jb's 52]

To add,

Try the CC in the loop w/o the footswitch attached and loop assigned to "On All".
Might be something funky with the f/s and/or the cable.

 

[Scary]

Could be a problem with the FX unit, a cable, or even the Mark V's footswitch cable. Remove the FX but keep the loop enabled first to rule out the footswitch.

 

[ixoye777]

It's prob. just the cable to the MV footswitch, unplug it (at the footswitch side) and plug it back in nice a snug.

 

[Ben Gregory]

All of these are good ideas, I have tried them and I am still unsure what it is. It starting working again today and I had changed a cable, but then it cut off very suddenly. I guess it might be the tube in the v6 slot, but that surprises me since I have not used the fx loop that often until recently. I will remove the cover and see if the v6 preamp tube lights up. Thanks for the sugestions!!