40h LEDs not working on powerup #082

  • I recently bought a 40h 2nd hand (#082), and am enjoying playing with it so much. My duo's live set has taken on so much more life and variation with the pretty buttons.

    Thinking about using the analog ports for some pots / accelerometer I decided to open it up. Everything inside was great and I decided to give the pads a clean (as per the 'care' section in the wiki) and lightly dusted them.

    After putting it back together I have found that when I plug the 40h in the lights don't turn on and can't be controlled through software. As per usual I pulled out the plug and reinserted it, hoping for a different result which thankfully I got.

    So my problem is that whenever I've had my 40h unplugged and I go to use it, I have to plug it in, then unplug it, then replug. Needless to say this is a little irritating and I'm curious what is happening.

    NB: I was extremely careful in opening the insides and the nylon spacers were placed back exactly the same way etc.

  • that's incredibly weird. it's totally predictable? it'll turn on the second time always?

  • Thinking about it logically I couldn't construct a reason for this occurrence.. Thought about charging capacitors on the 7221 chip but that doesn't make a lot of sense after looking at the schematic.

    Yes, the second time it always turns on. The only time it won't turn on is if it has been sitting unplugged for a while (maybe overnight?)... I will do some more experimentation to see if I can get it to reliably occur - only problem is this requires leaving the 40h unplugged for extended periods of time!

    I'll post back if it continues to occur.

  • hmm. if you'd like to ship the logic board over here i could take a look, reflash the firmware, etc. or if you're traveling on the east coast you're welcome to stop by (are you still in the bay area?)

  • Well it has continued - I'll reconsider the time to ~1 hour unplugged before it requires the 'charging' plug as I have come to call it..

    I'm afraid you must have you're wires crossed a little though re: 'bay area', as I'm across the pacific in Melbourne... Still thanks for the offer for support.

    I'll crack it open again this afternoon and make sure there is nothing strange going on (I also think there's a little talc under two of the buttons.. must clean). It's not a huge problem, but I might see how I go replacing the capacitors if it continues to bug me.

    P.S. I'm ordering hi-brightness R/G led's at the moment - about to sit down and redesign the keypad board, and logic board (2 x 7221) and firmware... argggg!!!!! I'll let you know how it pans out.

  • sounds good. and yes i'm totally confusing forum usernames.

    if it persists i can ship/swap the logic board, let me know.