m5 sound goes off randomly and unpredictably

[tryfonas78]

Sorry, still having the same problem with them5  going out  raNDOMLY  AND UNPREDICTABLY. WITH THE ORIGINAL POWER SUPPLY.  Ways to replicate the problem include:

1) repeatedly stomping the on/off footswitch (this is intermittent, and not at all predictable, but it does happen)

2) hitting the tap tempo switch (again, intermittent, but it *will* replicate the problem eventually)

3) turning on / off another pedal in the chain

Changing presets and then returning to the one I was using resets it and the sound returns, but this is a serious problem.

 

 

 

SWITCH OFF /ON    IS  THE SOLUTION  BUT  NOT  AN OPTION IN LIVE  AT ALL  PLEASE  HELP

 

 

 ISSUE IS  BEING  FILED  SINCE  2012.  NO  SOLUTION   GIVEN.  OR  I MA  AWARE

[JHV3]

Hello!!

 

Your issue is directly related to the ribbon cable connector between the main and UI PCBs, and I would argue that 99% of all problems found in the M5 originate here. On rare occasion does someone damage the pedal from inadvertent and extended exposure to an AC power supply instead of the proper 9V DC. 

 

This cable assembly is formed by compressing a ribbon cable into self-aligning "forks" for each wire and relative pin/socket, an electrical connection is made as each fork pinches and breaks through the insulation and ultimately compressing the stranded wire for a connection. For whatever reason, during assembly some of these forks were forced open just enough to either break the insulation of an adjacent wire and make contact or not make an effective connection to its intended path. Just one short/break can short signals/power together, float critical connections, or create just enough resistance to render the unit short of reliable behavior. Any trauma, vibration or pressure to the pedal could exacerbate the issue resulting in failure. 

 

To fix this from ever happening again, each tapered fork will need to be compressed together by hand (needle nose pliers) in such a way that both ensures clearance from adjacent wires and sufficient connection to it's intended wire. 

 

If done with great precision the covers/locks for both ends of connector will reassemble with a bit of finess (overlapping each fork onto itself will increase its depth making it very difficult to fit into it's slot). If this is the case either correct each connection or cover all of in a generous bead of Automotive GOOP. This clear adhesive will effectively secure and isolate each fork and all but eliminate the chance of future shorts and breaks. In addition, this particular version of GOOP is remarkably robust while still leaving the option of being removed in the future without damaging the pieces it secures.

 

There's a notable amount of discussion addressing this and related power/audio issues in forums (and one particular youtube video) that claims the fix involves replacing the less conductive "painted" stock screws from the bottom of case with those that are more conductive. The truth is, there is little to no significant difference between the stock screws and bare copper. The stock screws are not painted at all, they're treated with a process which aesthetically turns them black with the added benefit of rust prevention. When measured with an Ohm meter you'll find no difference in resistance between old and new. Fundamentally, these mechanical connections are not critical to the pedals function at all, it will still work without the bottom cover. 

 

Because the larger main PCB is secured by the front two screws  the I/O jacks (which has resulted in a constant tension on the main PCB) removing the front screws will allow the PCB to straighten. The simple movement of the PCB, when swapping out the screws, is just enough to temporarily make or break the short (or at least increase the resistance) between the faulty connector crimps in the ribbon cable either making a correct connection or breaking an offensive circuit. Over time, use, vibration, trauma, transportation etc. this connection/break could eventually recur  just enough to cause the same issue.

 

To fix it once and for all, address these connections properly and you'll never have the problem again!

(FYI: One issue that is screw related is the mistake of using the longer screws from the front in the rear positions [typically after removing the rubber feet to allow more surface area for velcro adhesion on a pedal board] which will damage a decoupling capacitor and/or the PCB underneath each location. This won't necessarily brick the pedal, but will defeat an intentional component placement.)

[tms1970]

I've had my M5 for years and years and for the first few it worked fine.

 

Then suddenly the power issues began, screen flickering / sound cutting out / just as always described by everyone else.

 

I took all the screws out and sanded down all the areas suggested in other posts and...blimey... it started working properly again...

 

The euphoria was short lived and 6 months or so later the issue reappeared.

 

The M5 had been collecting dust on a shelf for years, never wanting to throw it away but not being able to use it....

 

Then I found this article (the one we're reading) and took my M5 apart for one final go!

 

 

I managed to clear the glue off the ribbons (using a small knife, carfeully!) and then pulled the ribbons so they disconnected.

 

I don't have magnify-vision so there's no chance I could take each wire apart and check the connection individually, however using long nose pliers to push the wires down flush(er) and then reusing the mini knife to scrape away the little bits of plastic misplaced by the wires connecting (*this'll make sense when your doing it) HAS WORKED!

 

I put the ribbon connectors back together, tested the pedal and it stays on all the time, no power issues at all...

 

It's nice to have this pedal back on my pedal board.

 

THANKS FOR THE FIX! The only one that actually worked.

[RaineMakerMusic]

I am having this SAME issue.....thinking its been my guitar for a year now.....

All of a sudden two weeks ago....in the middle of a gig....BLUE/WHITE  screen....It just tanked.

I will try to do what you posted.....its better than dropping more dough for the same pedal....which i love...but irks me.

Thanks!

[RaineMakerMusic]

Just found this..... tried it....and so far so good.

and....it was posted THREE years ago....So apparently this has been an issue for quite some time....and defect in the build. 

[tryfonas78]

i am the  first to open this  thread   and  after  one  year i  did  noticed  that the  answer  was  waiting  for  me.....THANK YOU SO MUCH  FOR YOUR SOLUTION TO THIS  PROBLEM. I MIGHT OPENED THE   THREAD  BUT THIS  WILL  HELP THOUSANDS OF USERS.   YOU  ARE  100% CORRECT IN THE   ASSESMENT OF THE  PROBLEM  AND THE SOLUTION. 

 

 PROBLEM SOLVED  IWISH  LINE6  COULD   SEE THIS THREAD  CO Z THE    SUPPORT  WERE  GIVING   F U C K   ALL  ANSWERS     EG  USE   CORRECT  POWER  ......  OR  NO  REPLY AT  ALL  BIG THANK YOU 

JHV3

 

 

Hello!!

 

Your issue is directly related to the ribbon cable connector between the main and UI PCBs, and I would argue that 99% of all problems found in the M5 originate here. On rare occasion does someone damage the pedal from inadvertent and extended exposure to an AC power supply instead of the proper 9V DC. 

 

This cable assembly is formed by compressing a ribbon cable into self-aligning "forks" for each wire and relative pin/socket, an electrical connection is made as each fork pinches and breaks through the insulation and ultimately compressing the stranded wire for a connection. For whatever reason, during assembly some of these forks were forced open just enough to either break the insulation of an adjacent wire and make contact or not make an effective connection to its intended path. Just one short/break can short signals/power together, float critical connections, or create just enough resistance to render the unit short of reliable behavior. Any trauma, vibration or pressure to the pedal could exacerbate the issue resulting in failure. 

 

To fix this from ever happening again, each tapered fork will need to be compressed together by hand (needle nose pliers) in such a way that both ensures clearance from adjacent wires and sufficient connection to it's intended wire. 

 

If done with great precision the covers/locks for both ends of connector will reassemble with a bit of finess (overlapping each fork onto itself will increase its depth making it very difficult to fit into it's slot). If this is the case either correct each connection or cover all of in a generous bead of Automotive GOOP. This clear adhesive will effectively secure and isolate each fork and all but eliminate the chance of future shorts and breaks. In addition, this particular version of GOOP is remarkably robust while still leaving the option of being removed in the future without damaging the pieces it secures.

 

There's a notable amount of discussion addressing this and related power/audio issues in forums (and one particular youtube video) that claims the fix involves replacing the less conductive "painted" stock screws from the bottom of case with those that are more conductive. The truth is, there is little to no significant difference between the stock screws and bare copper. The stock screws are not painted at all, they're treated with a process which aesthetically turns them black with the added benefit of rust prevention. When measured with an Ohm meter you'll find no difference in resistance between old and new. Fundamentally, these mechanical connections are not critical to the pedals function at all, it will still work without the bottom cover. 

 

Because the larger main PCB is secured by the front two screws  the I/O jacks (which has resulted in a constant tension on the main PCB) removing the front screws will allow the PCB to straighten. The simple movement of the PCB, when swapping out the screws, is just enough to temporarily make or break the short (or at least increase the resistance) between the faulty connector crimps in the ribbon cable either making a correct connection or breaking an offensive circuit. Over time, use, vibration, trauma, transportation etc. this connection/break could eventually recur  just enough to cause the same issue.

 

To fix it once and for all, address these connections properly and you'll never have the problem again!

(FYI: One issue that is screw related is the mistake of using the longer screws from the front in the rear positions [typically after removing the rubber feet to allow more surface area for velcro adhesion on a pedal board] which will damage a decoupling capacitor and/or the PCB underneath each location. This won't necessarily brick the pedal, but will defeat an intentional component placement.)