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just built LXR none of the buttons work and no LEDS

owensandsowensands
edited December 2013 in Troubleshooting
The unit turns on and the LCD comes on with version and then goes to COA fine Wav screen. I updated firmware twice. USB is detected by the computer etc. Buttons don't work at all. Not a single one. No LEDs either including voice one that is supposed to be lit when it boots I guess. Ive re soldered all IC sockets to no avail. All ICs I checked for orientation at least three times over. Im stumped. I didnt do this from kit but 95% parts are from the BOM from mouser including the LEDs.
Any ideas?
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Comments

  • cj55cj55
    edited December 2013
    Check all the resistor networks for right orientation. Or maybe you have swapped the 74HC595 and 74HC165 ICs?
  • owensandsowensands
    checked it all. All are correct. Went over it at least 3,4 times now.
  • cj55cj55
    Is the encoder working? And the pots?
  • owensandsowensands
    yep
  • cj55cj55
    edited December 2013
    Have a look at the frontpanel schematics. Page 6 for the inputs (buttons) and page 7 for the outputs (LEDs)

    http://www.sonic-potions.com/sites/default/files/documents/FrontpanelSchematic.pdf
  • owensandsowensands
    Really not that great with schematics. What should I be looking for?
  • LindeborgLindeborg
    edited December 2013
    Checked the 74hc165s and 74hc595 so that they are in the right place and right way?
  • loderbastloderbast
    there is not that much to it.
    the buttons have the resistor networks for pulldown. then go to 74hc165 parallel to serrial shift registers which are chained togeter then go directly to the atmega.

    with the leds its kind of the other way around : atmega -> 75hc595 (which are serrial to parallel) -> leds with current limiting resistors

    things to check:

    are the ics oriented right, in the right place and sitting nicely in their sockets?
    are the resistor networks orientated right?

    is the atmega socket soldered right?

    Dout / Din _Data ,_Shift, _Clock and _Load lines not shorted to ground or something?

    The Shift registers are kind of chained together. so if there is something wrong with the first ones in the chain, the others wont work aswell. (those would be U2 and U3 in the schematic)

    please check all this once more and then upload hires pictures of both sides of the board if that won't help. there are a bunch of people who are really good at spotting stuff in pictures. it works on the mutable instruments forum all the time for troubleshooting.

    don't despair. you'll get it working for shure. chances are you'll learn a bit about electronics on the way ;)




  • julianjulian
    loderbast is right.

    both, input and output are a chain, so if the first IC has problems, the others won't work, too.
    First check the soldering for shorts at the AVR and U2 / U3

    if you take a look at page 4 of the schematic, you see the AVR.
    You are interested in the DIN... and DOUT... lines.
    each have 3 wires, LOAD,SHIFT, DATA
    DIN (digital in) is for the buttons (pin 27-29 on the avr)
    DOUT (digital out) for the LEDs (pin 18-20 on the avr)

    On page 6 are the buttons.
    check that you have a connection between DIN_DATA and U2, Pin9
    this is where the shift register (165) forwards the data to the AVR
    Also check that Clock and Load are connected to pin 2 and 1 of U2

    Same for page 7 with the LEDs
    DOUT_DATA to pin 14
    Shift to 11
    and Load to 12


  • owensandsowensands
    yep checked everything over an over re soldered the atmega because my friend told me all this as well. All ICs All resistor networks are orientated right etc. Im thinking its a bad IC in the chain at this point but I don't have any extra to swap. But that seems weird to me since both the LEDS and the buttons dont work. A bad 165 and 595 maybe? How could that be. Going to take it to my friends and put it on the scope to see where the data stops. He als has extra ICs
  • nightworxxnightworxx
    edited December 2013
    Hm, failing 595s are not really new to me. Had once a complete charge ordered at the big R, which really sucked...
    And about the 165: it is as far as i know one of those ICs of th DIY world, which is really ESD sensitive.

    My advice: remove them, check for bent pins, or a wonky socket. If all looks ok, replace them, they cost just a few cents. And if you are planning to do more DIY projects: order masses of them - you will need them !
  • julianjulian
    You could try swapping the 595 ics. They are chained. If the 1st isn't working, none work. If another one isn't working, at least the 1st will work.

    Other than that if you have access to a scope that's great!

  • billieblazebillieblaze
    ya, so i put a scope on it for him..   not really seeing clock pulses from the AVR to either in or output SR chains..    thoughts? 
  • billieblazebillieblaze
    i'm seeing random blips, but nothing that looks like a steady running clock..  this is both at the AVR pins and the SR socket..  

  • owensandsowensands
    Digital out clock
  • owensandsowensands
    edited December 2013
    And this is the digital in
  • billieblazebillieblaze
    i should also note that we checked continuity from the avr thru all din / dout lines..    checked res networks, caps, etc..    chip orientation is good.. and we touched up many solder joints, but like i say, theres contiunity!  
  • billieblazebillieblaze
    even swapped the avr with my lxr  

  • owensandsowensands
    edited January 2014
    https://dl.dropboxusercontent.com/u/21792288/LXR Build.zip

    here are images of front and back super high res taken with canon rebel
    Also My AVR worked in Billie's unit too.
  • owensandsowensands
    if I remove all ICs except u2 and u3 and the 4050 should I be able to click the first 8 buttons in the seq and the leds light up?? I would like to insert the least amount of ICs to get something. I would think this is it right? Im just guessing here.
  • julianjulian
    I'm looking over you pics now and think about what causes these issues.

    you are right.
    if only u2 and u3 are inserted, the 1st 8 buttons and LEDs should work.
    that would be step 1-8 for the buttons
    and step LEDs 9 to 16

  • julianjulian
    is the encoder and the knobs working?
    can you change values on screen?
  • owensandsowensands
    yes
  • owensandsowensands
    ok so if I just put in u2 and u3 I still shouldnt see anything then because buttons for 1-8 should light up 1-8 but that is a different IC u7 right?
  • owensandsowensands
    I also just inserted the entire chain of 595s without any 165's(also with the 4050). This should result in the voice led lighting on boot no? They are independent chains right? Not counting the button pushes and led lighting which happens with the data flow from 165 chain to AVR then AVR to 595 chain. I would consider this to be indirectly dependent since its VIA the avr.
  • julianjulian
    yeah - U7 is LED 1-8
    But Then you need both, U7 and U3
  • julianjulian
    buttons have nothing to do with the LEDs per se.
    If you just insert the 595's, the voice 1 LED and the voice mode LED should be lit after the boot (when the screen shows coa,fin,wav...)

    so you can leave out all the 165
  • julianjulian
    the 4050 is just there to talk to the sd card.
  • owensandsowensands
    right yeah I tried that and voice light did not light. I dont think it has anything to do with either of the chains since both chains are completely dead. Ive used good ICs in both the beginning of the chains and still nothing. Why am I not getting a steady clock? did you see what billie wrote about the clock signal on the scope?
  • julianjulian
    U11 is the voice mode LED
    and U13 voice 1-7

    what confuses me is that billieblaze could not measure a clock on either the DIN nor the DOUT line.
    both the DIN and DOUT circuits are totally independent. So somehow I suspect there must be a short somewhere between those lines.

    Did you also tried to measure the DATA and SHIFT lines with the scope?

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