Only one LED on, no response and blank diplay

I dont know what i did wrong in the asambely … I bought the kit version so its the standard mkII filter board. i checked the filter board and it seemed to indicate the right voltage the right places so i assume that part is working.

So i think the error must be in the Main board, but i have checked all the soldering and i cant seem to find anything wrong.

But when i turn it on all that happens it that the LED to the furthest right light up and otherwise its all blank. I have removed the LCD again just to make sure it was not doing something wrong there. But still same problem. One LED to the furthest right light up and no buttons or anything are working.

Is there anybody that has an idea to where i can go from here? …

I can take pictures of the boards if that would help any.

Yes, photos of your boards please.

Maybe you have swapped the two 74hc chips on the control board?

Ok :slight_smile: i will take photos when i get home from work.

LCD display is blank: that usually means the contrast trimmer isnt adjusted. Have you tried turning it to both ends and see what happens? If the microcontroller is not working properly (=display is not initialized during startup) then the first line should be black and the second line white (or was it the other way around?)
Try adjusting the contrast trimmer until you can see something.

Here is a link for the pictures:
they were too big to attach here…

TheSlowGrowth> i did not pay much attention to the LCD as the unit is supposed to work even when the display is not connected as far as i read from the instructions. So i dis-mounted the display again to make sure that was not the problem. But still the buttons are un-responsive and only the one on the far right is lit up.

Have you checked, if the 74HC595 and 74HC165 are in the right place? It’s not recognizable from your pictures.

ah! your are right … they where placed wrongly … doh! … well now i just need to get a power supply (used my friends where we assembled) and test it out if it works now :smiley: … thanks a lot for the help :slight_smile:

Argh… now i got all the buttons working and the display is up and running… BUT! … no sound and no midi … i put it into Jam mode … but nothing comes out of the audio… :frowning:

Have you soldered the bridges for the audio in and audio out?
Edit: never mind me asking, just saw it on your pictures.

Did a bit of recon, R is reflow, circles and ? marks are points I’d inspect carefully. I’m sure I missed some, and totally marked a lot that are actually decent joints, that were obscured or blurred by the camera/light. Taking pictures of soldering is a bit of a tricky business after all… I’d start at the bottom, and work my way up as needed. Particularly the ones on the audio connectors look slightly dodgy…


Ah! thank you so much for taking the time! very very nice of you … i will go through it all tonight, and hopefully that will get me somewhere … :slight_smile: … but it is a bit worrying that the midi is not responding either as it seems they audio and midi are not really connected in any way… but maybe i should just take it one issue at a time :wink:

How did you establish that midi didn’t work?
And are you absolutely sure everything midi-wise is set up correctly? Channel, cables, ports on both ends?