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Problem with random mode, keyboard mode
Moderators: altitude, adafruit_support_bill, adafruit, hamburgers, phono

Please be positive and constructive with your questions and comments.

Problem with random mode, keyboard mode

by relaxing on Mon Jul 11, 2005 11:18 am

In random mode, the b0x plays to the end of the random sequence and then makes a popping noise as though something is shorting or resetting, and the 5 or so rightmost LEDs light up. then the same random sequence starts over.

In keyboard mode, the pitches produced are erratic and don't follow any order or progression of pitch.


Where should I begin debugging? I can post sound files if that would help.

relaxing
 
Posts: 59
Joined: Thu Mar 24, 2005 11:22 am

by Guest on Mon Jul 11, 2005 1:49 pm

Try reflashing the firmware
Guest
 

by relaxing on Mon Jul 11, 2005 10:35 pm

reflashed. no luck.


further details -- pressing keys S8, S10, S19, or S21 in keyboard mode causes the same "reset" effect. All other keys produce weird, resonating tones.

it's always LEDs 16, 25, 26, 27, 39, and 40 that light up after the reset.

relaxing
 
Posts: 59
Joined: Thu Mar 24, 2005 11:22 am

by Guest on Tue Jul 12, 2005 12:49 am

all of those leds are on the same latch
but i doubt that it has anything to do with the problem

its possible that one of your data lines from the microcontroller
to the d to a has a short
so when it tries to play certain notes it shorts out the micrcontroller
check pins 12 13 14 and 15 of ic9 and pins 21 - 28 of the micro

do any of the other modes work
can it be slaved to midi
which buttons cause failure if you shift up an octave or down an octave

check that all of your components are orientated correctly
and that there are no shorted traces
and components arent touching
especially the 200k resistors
it sounds like one of the microcontroller or latch output pins is shorting
to something else
Guest
 

by relaxing on Tue Jul 12, 2005 7:12 pm

ok. Pin 15 of IC9 -- R80 is shorted to ground.

But I don't see how this is be happening. There are no bad connections I can see.

Also, it doesn't seem to respond to midi.

p.s. thank you for your help!

relaxing
 
Posts: 59
Joined: Thu Mar 24, 2005 11:22 am

by Guest on Wed Jul 13, 2005 4:00 am

pin15 of ic9 connects to r81
is r80 also shorted to ground

remove r81 and check to see if its good
its possible its a bad part
then check to see if pin15 is still shorted to ground
if it is shorted check the traces for bad silk screening
its possible ic9 is bad although unlikely

you could remove ic9 and push all sorts of buttons
to verify that it doesnt crash
it wont change notes but it should play
Guest
 

by relaxing on Wed Jul 13, 2005 6:00 pm

I desoldered only pin 15, and that pin still has continuity to ground. And the problem persists.

This would point to a bad chip, correct? I'd guess internal to IC9, pin 15 is somehow shorted to pin 8.

also now it responds to midi. although the notes are still all wrong.

relaxing
 
Posts: 59
Joined: Thu Mar 24, 2005 11:22 am

by Guest on Thu Jul 14, 2005 1:26 am

it sounds llike ic9 is bad
remove it and measure the continuity at the traces
before putting the new one in
just to make sure there are no other problems
Guest
 

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