FX Loop Issue

The Boogie Board

Help Support The Boogie Board:

This site may earn a commission from merchant affiliate links, including eBay, Amazon, and others.

Mesa512

Member
Joined
Oct 20, 2015
Messages
14
Reaction score
0
Hello,

So I’ve been struggling with trying to figure out the issue with my FX Loop in my Mark V Head.

The signal path is very simple. FX send -> tc electronics flashback input -> tc electronics output -> FX return

This worked for years and then one day, it just stopped. I have tried troubleshooting it quite a bit. I isolated the pedal by plugging my guitar into the guitar pedal input and then directly jacking into my amps input and the pedal works fine.

I also replaced my V6 preamp tube thinking that was the issue. I am about ready to bring it into a Mesa repair shop but wanted to see if you guys can think of something that I may be missing before doing so.

Thanks
 
Curious could the HARD BYPASS/LOOP ACTIVE mini toggle possibly be in the bypass position? Plus do you see the FX led active on the front panel?
 
Okay so I confirmed the HARD BYPASS/ LOOP ACTIVE is NOT in the bypass position. However, now that you mentioned it I checked and my FX LED is not on. For loop assign I have it currently set to the foot switch. If I click the FX Loop on on the foot switch the LED indicator on the foot switch will light up but not on the amp. If I change the loop assign to all channels the FX LED will turn on the amp. I am so confused now. What do you guys think?
 
Mesa512 said:
Okay so I confirmed the HARD BYPASS/ LOOP ACTIVE is NOT in the bypass position. However, now that you mentioned it I checked and my FX LED is not on. For loop assign I have it currently set to the foot switch. If I click the FX Loop on on the foot switch the LED indicator on the foot switch will light up but not on the amp. If I change the loop assign to all channels the FX LED will turn on the amp. I am so confused now. What do you guys think?

Ok sounds like you're zeroing in on it. So if you disconnect the foot switch cable from the amp, set the Channel Select to Ch1, Loop assign to Ch 1, the front LED should be on. At that point is the loop functioning as expected? If so I would think perhaps your footswitch is not functioning properly.
 
rarebitusa said:
Mesa512 said:
Okay so I confirmed the HARD BYPASS/ LOOP ACTIVE is NOT in the bypass position. However, now that you mentioned it I checked and my FX LED is not on. For loop assign I have it currently set to the foot switch. If I click the FX Loop on on the foot switch the LED indicator on the foot switch will light up but not on the amp. If I change the loop assign to all channels the FX LED will turn on the amp. I am so confused now. What do you guys think?

Ok sounds like you're zeroing in on it. So if you disconnect the foot switch cable from the amp, set the Channel Select to Ch1, Loop assign to Ch 1, the front LED should be on. At that point is the loop functioning as expected? If so I would think perhaps your footswitch is not functioning properly.

Okay, you're the man. So I did exactly as you said. I set channel select to channel 3, and loop assign to channel 3 after disconnecting my Mark V footswitch and bingo my effect loop is finally working again. So it looks like I will be ordering a replacement footswtich to get this amp back up and fully functional. I really appreciate your help. Thank you again!
 
Mesa512 said:
rarebitusa said:
Mesa512 said:
Okay so I confirmed the HARD BYPASS/ LOOP ACTIVE is NOT in the bypass position. However, now that you mentioned it I checked and my FX LED is not on. For loop assign I have it currently set to the foot switch. If I click the FX Loop on on the foot switch the LED indicator on the foot switch will light up but not on the amp. If I change the loop assign to all channels the FX LED will turn on the amp. I am so confused now. What do you guys think?

Ok sounds like you're zeroing in on it. So if you disconnect the foot switch cable from the amp, set the Channel Select to Ch1, Loop assign to Ch 1, the front LED should be on. At that point is the loop functioning as expected? If so I would think perhaps your footswitch is not functioning properly.

Okay, you're the man. So I did exactly as you said. I set channel select to channel 3, and loop assign to channel 3 after disconnecting my Mark V footswitch and bingo my effect loop is finally working again. So it looks like I will be ordering a replacement footswtich to get this amp back up and fully functional. I really appreciate your help. Thank you again!

no worries... most excellent that's progress... now I would suggest before grabbing a new footswitch to consider testing out the cable and also verify the connectors on the footswitch and on the amp look ok. Since the footswitch led comes on it's possible that there may bad connection between the footswitch and the amp.
 
rarebitusa said:
Mesa512 said:
rarebitusa said:
Ok sounds like you're zeroing in on it. So if you disconnect the foot switch cable from the amp, set the Channel Select to Ch1, Loop assign to Ch 1, the front LED should be on. At that point is the loop functioning as expected? If so I would think perhaps your footswitch is not functioning properly.

Okay, you're the man. So I did exactly as you said. I set channel select to channel 3, and loop assign to channel 3 after disconnecting my Mark V footswitch and bingo my effect loop is finally working again. So it looks like I will be ordering a replacement footswtich to get this amp back up and fully functional. I really appreciate your help. Thank you again!

no worries... most excellent that's progress... now I would suggest before grabbing a new footswitch to consider testing out the cable and also verify the connectors on the footswitch and on the amp look ok. Since the footswitch led comes on it's possible that there may bad connection between the footswitch and the amp.

Yes, I will be sure to ensure the cable and connectors are working properly. It would be very foolish of me to replace a $200 footswitch when cable is to blame. I lot cheaper of a repair. Thank you again for all your help.
 
Luck would have it that my friend had a spare footswitch cable for my Mark V. I plug the cable in and BINGO, my FX loop finally works again. I am shocked that it was my cable this whole time. I was thinking there was a very complex issue with my amp that was going to require me to send it back to Mesa to have repaired. Thanks for your help!
 
Mesa512 said:
Luck would have it that my friend had a spare footswitch cable for my Mark V. I plug the cable in and BINGO, my FX loop finally works again. I am shocked that it was my cable this whole time. I was thinking there was a very complex issue with my amp that was going to require me to send it back to Mesa to have repaired. Thanks for your help!

Oh sweet... that's great. congrats. Curious can you tell what's wrong with the bad cable? sorry I'm just sort of a nerd about these things. :)
 
Yes, the middle pin must have broke somehow and I never noticed. I did move back in 2017 and somehow it must have broken off by mistake without me knowing. It will still plug in just fine, so I never really paid any attention to it.
 
Mesa512 said:
Yes, the middle pin must have broke somehow and I never noticed. I did move back in 2017 and somehow it must have broken off by mistake without me knowing. It will still plug in just fine, so I never really paid any attention to it.

Well of all scenarios that's probably the least expensive one to have to deal with. :)
 

Latest posts

Back
Top