e-licktronic Forum

hello DIY fans!

first of all, thanks for the great project, really satisfied with the sound and workflow.

i got an assembled unit but it needed calibration/exchange of resistors etc.
during the process i made a mistake that i caused a short circuit between the two boards. the sequencer was running and after a second it was fucked up.

when you power the yocto mode-selector is working somehow and changes LED 3,4,6 and a random pattern of steps 2-16.
i guess the voices are still working (fingers crossed).

i tried to find the problem so i found IC4 getting really hot. i changed IC3, IC4, IC5, IC9 but still its not working. IC4 is not getting hot anymore though.

the voltages on the main board is 5V, 14,8V, -14,8V so i guess it might be still a problem with the all the other ICs.
i will swap IC 2,7,8 but then it could be possibly IC1 and IC10.
do you have voltages at several pins to check if they are working?

was it possible to order IC1 and IC10 if i do not succeed? might be something else broken on the IO-Board?

thank you so much, i hope its possible to fix it!
jacob

That also happened to me. I'm not sure I short circuited, but that seems the most logical explanation.

Now, all 6 LEDS are on all the time, and it seems that the CPU reads the Shift button to be on all the time, since I don't have to press it to Init the EEP or set an instrument midi channel using it as an expander.

I know this does not help you, but I'm in the same boat.

hi jonhallur!
thx for the reply!
vincent told me to order ICs 1-10 of the sequencer. i will replace the shift registers first and if it still fails i have to find a solution to write on the Atmel.
viewtopic.php?f=16&t=185&p=1121&hilit=bootloader#p1121

the Bootloader and code are available on the forum he said.
viewtopic.php?f=17&t=180&start=10

would an arduino board work as a USB-serial interface to write down to the amtel. or what else would i need?

to be continued:)

jac

Hi,

Small status update report. I desoldered IC7 (that took a very long time) replaced it with a socket and a new 165N.

The sequencer now works.

Hope your fix goes as well as mine.

Thx for the update! We were also successful! After replacing IC2-10 it was still not working. Checked all diodes etc.
finally with a scope there was no correct clock signal for the shift registers from the UC present. It looked like a falling moog saw instead of a sharp square wave. So we put a 1k resistor between clock out and ground for extra load of the (possible) damaged pull down transistor of the port. Et voila. The clock pulse was a lot narrower and drives all IC successfull. Dirty hack, but it works:)