40h problem

  • hi guys,

    my 40h recently started sending random pad firings when i pick it up, or move the unit. confirmed in 40_test. mostly along columns 0 and 7 (the extremities). still useable if i keep it in one place, but a pain if i wanna pick it up and use it. is there a loose connection somewhere that i could solder back on if i open it up?

  • dang thats a bummer
    maby something inside slipped?
    idk ive never looked into whats inside it :P

    I just use what outside it (the apps)

  • Brian has been pretty fast at pinpointing any problems so far. I wouldn't know what's wrong, yeah sounds like something is loose, some bad solder perhaps. I had that problem, luckily it was easy to spot and easy to fix. Hardest thing was getting the glued base open. Worst case scenario, you'll have to send it back for repairs.

  • is it an original? or a kit?

    that sounds quite bizarre, though i'm certain i could spot it on inspection. does anything feel or sound loose? what serial number do you have?

  • original, serial m40h0029 (yes it's me). nothing's obviously wrong, like loose components or anything. funny thing is it's stopped doing it now, took it to my mate's house in my backpack, where it broke, then took it back home and it seems ok. i'll keep an eye on it and if it develops again i'll take some video of the problem.

    just ffi brian, if you could let me know the hex wrench size i need to get into it, as well as the glue you stick it back together with, that'd be awesome.

  • 1/16"

    100% silicone glue


    where are you located?

  • uk, so would like to avoid posting it back as much as possible (hilariously large customs charges). seems fine now though, i'll let you know what develops. thanks for the link.

  • Hi,

    Just finished buidling my first of two 40h's. In test mode I also noticed random pad triggers. Setting only the leds on/off gives no problems.

    In sequencer app. it's seems to be gone ??? Is this something related to the test app?
    At the moment I'm using monome serial on win XP at 40h_base0400.


  • i was wondering if it was app related but the events were happening without any button presses (just moving the unit around) so i'm 99% sure it's a hardware issue. interesting you've got the same thing though.

  • do you have a top plate on your 40h? the silicon pads jiggling around can cause this.

    other than that it has to be the ribbon cables.
    - headers on the cables aren't cinched down tight
    - they're not full seated onto the connector to the PCB
    -- if you look at the header on the PCB it's a tight fit, I actually bent mine out at a bit of an angle to get the ribbon cable on there tightly

  • No topplate mounted yet so this can not be the cause. I will check the ribbon cables on their fixation.


  • i think tone meant that without a topplate, the silicon pads can jiggle and cause the problem you mentioned.

  • Well as the silicon pads are correctly positioned on the PCB, is it really that sensitive? I will check it.


  • Just checked. Pressed the ribbons to ensure good contacts.
    Now no problems occur! I've noticed some difference in the test app. Having the problem I saw the pad grid 'scanning' the rows toggling pads randomly. Now even with some pads toggled the pad grid refresh rate seems more stable and I see no flickering in the pad grid.


  • great! maybe that's my problem too then.