Line6 M5: grounding issue?

Discussion in 'Effects [BG]' started by Adamixoye, Mar 2, 2014.


  1. Adamixoye

    Adamixoye A PT Pro is cool for worship, right? Supporting Member

    Joined:
    Apr 9, 2012
    My Line6 M5 has gradually become quite flaky. This morning at worship practice it cut out completely. Fortunately it only took me a couple minutes to figure out where the problem was and take it out of my chain.

    Some of the (intermittent) problems are as follows:

    (1) Excessively flickers on power up
    (2) Fails to power up at all
    (3) Unwanted power cycling when pressing on foot switches
    (4) Audio cuts out, generally not fixed until power cycling
    (5) Other weird randomness (mode switching, preset weirdness, etc.)

    I didn't find any help searching TB, but I found this thread on the Line6 website:
    http://line6.com/supportarchivenew/thread/88421

    The third post (out of only five on that page) seems to have a very interesting diagnosis and solution, to do with grounding of the pedal. I ran it by a friend of mine who is an expert in electronics (but no pedal specific experience), and he thought it was at least plausible, and more like probable, that this is indeed a grounding issue. And I wanted to throw it out there to you TBers who might have both the electronics and pedal expertise to weigh in. Or, any specific M5 experience would be great, too.

    For more context, I bought my M5 used. The rubber feet and screws had already been removed, so that the bottom piece of the metal chassis is a bit loose (but still held in place by, I think, one or more screws on the side). It is connected to a PT Pro by Velcro. It is powered by a 9V 400 mA outlet on a Pedal Power Mondo. (There is some conflicting info out there about whether or not the original power supply is 250 mA or 500 mA. I have seen third party claims that 400 mA should definitely be adequate.)

    So...any thoughts would be greatly appreciated!
  2. JonnyAngle

    JonnyAngle Supporting Member

    Joined:
    Nov 24, 2008
    Location:
    Maple Grove, MN
    It us absolutely possible. It happened to mine, and I followed that thread and haven't had any problems since
  3. shark561

    shark561

    Joined:
    Jan 14, 2009
    Mine suffers from #4 audio cutting out. I'll try that fix thanks!
  4. blixild

    blixild Supporting Member

    Joined:
    Mar 4, 2006
    Location:
    Buffalo, NY
    The guitar player in my bands has been having this problem. He switched to a 1Spot power adapter and he hasn't had a problem since.
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  6. Adamixoye

    Adamixoye A PT Pro is cool for worship, right? Supporting Member

    Joined:
    Apr 9, 2012
    What was he using before---an outlet on a power supply like I am?
  7. Adamixoye

    Adamixoye A PT Pro is cool for worship, right? Supporting Member

    Joined:
    Apr 9, 2012
    And I ask because I'm really pretty sure the 9V 400 mA outlet should work, but I know if I contact Line6 that's the first thing they'll tell me (and it's used/out of warranty anyway).
  8. DagoMaino

    DagoMaino Supporting Member

    Joined:
    Feb 1, 2013
    I was told by the guy that sold me mine that if you remove the rubber feet you need to back off the screws on the plate or it will ground out... I never had to deal with it, but that's what I was told, so I'm passing it on.
  9. dannybuoy

    dannybuoy

    Joined:
    Aug 3, 2005
    Location:
    London, England
    Maybe you can insulate the inside of the base if this is the case? Funnily enough I had exactly the same problem with a Cave pedal I took apart the other day, when I put it back together it passed no sound even in bypass. I insulated the bottom panel with some tape and then it was fine!
  10. NicJimBass

    NicJimBass The Kirk Hammett of bass guitar! Supporting Member

    Joined:
    Nov 22, 2004
    Location:
    Lancaster, OH
    I personally had this issue with my M5, and I followed the advice given on the Line 6 forum link you posted. Changing the 4 or 5 painted screws to unpainted screws, which are easily found at any hardware store, fixed the issue. Good luck!
  11. Adamixoye

    Adamixoye A PT Pro is cool for worship, right? Supporting Member

    Joined:
    Apr 9, 2012
    As I said in my original post, I do not have the original feet and screws. Is there any chance you could describe the length/pitch/size to me? Did you scrape off the paint as well?
  12. Adamixoye

    Adamixoye A PT Pro is cool for worship, right? Supporting Member

    Joined:
    Apr 9, 2012
    I'm a little confused, but by "back off" you mean do not screw it back together as tightly?
  13. Adamixoye

    Adamixoye A PT Pro is cool for worship, right? Supporting Member

    Joined:
    Apr 9, 2012
    I am glad that this thread is helping a lot of people, and I'm glad (in an unfortunate, twisted way) that I'm not alone with this problem! I wish Line6 would just man up and make this solution more obvious. I will probably not be able to make it to a hardware store until Wednesday, so please keep the feedback coming.
  14. Adamixoye

    Adamixoye A PT Pro is cool for worship, right? Supporting Member

    Joined:
    Apr 9, 2012
    Any other feedback on this? I'm going to go to the hardware store tonight or tomorrow and try to find some unpainted screws.
  15. JonnyAngle

    JonnyAngle Supporting Member

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    Nov 24, 2008
    Location:
    Maple Grove, MN
    I don't think the screws are as important as scratching the paint so the body panels are making good contact
  16. Adamixoye

    Adamixoye A PT Pro is cool for worship, right? Supporting Member

    Joined:
    Apr 9, 2012
    I was a little confused at that part---he says something about removing the paint around the holes where you put the screws in, I take that to mean on the underside of the pedal. Did you scrape off paint anywhere else? Did you take the back off?
  17. JonnyAngle

    JonnyAngle Supporting Member

    Joined:
    Nov 24, 2008
    Location:
    Maple Grove, MN
    I completely disassembled mine. The locations where the screw joins 2 pieces of metal, i scraped the paint off of both sides so it's bare metal on bare metal.
  18. Adamixoye

    Adamixoye A PT Pro is cool for worship, right? Supporting Member

    Joined:
    Apr 9, 2012
    Okay, thanks. What did you use for scraping? Utility knife? Sandpaper?
  19. stinky634

    stinky634 Supporting Member

    Joined:
    Apr 19, 2001
    Location:
    Riverside CA
    Did you get this resolved??

    I got mine yesterday and haven't noticed any grounding issue, but I now that I see it's a widespread problem I am considering 'fixing' it in advance so I don't have unexpected issues down the road.
  20. Adamixoye

    Adamixoye A PT Pro is cool for worship, right? Supporting Member

    Joined:
    Apr 9, 2012
    Yes. I had trouble finding the best screws (and the ones I settled on may not be the best) but since I installed them I haven't had any trouble. On startup I will occasionally get two or three flickers (previously I could get maybe 5-10), but it's started up every time.

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