sammichFM CS not working

[freddy]

Guys,

 

I've build (excellently documented, BTW!) and tested both sammichFM PCBs and had no issue at all - no shorts, all voltages correct, powers up and works, i.e. I was able to upload firmware (the correct one before you ask), upload presets, play tunes from remote keyboard. The only issue is the CS - no LEDs lit, no enc/button works (apart from S3 which sends patch SysEx). I've measured HC165 and HC595 voltages, tested the paths from J8/J9 to the chips, paths from chips to LEDs, all seems okay but the HC595 outputs are all set to 0V. I'll measure the DIN matrix connections tomorrow if needed but this seems to be a general CS issue to me...

 

What else to look at? Anything to measure? I'm quite clueless at this moment  :no:

 

Looking forward! Cheers,

freddy

Edited March 24, 2013 by freddy

[nILS]

This sounds like one of the following:

 

- you've got the wrong firmware (it happens, simply upload the latest MIOS and then the latest sammichFM firmware to be on the safe side)

- you have the 165s and 595s mixed up

- you installed the resistor networks the wrong way around (make sure the dot on the network aligns with the dot on the silkscreen)

[freddy]

nILS, guys,

 

- you've got the wrong firmware (it happens, simply upload the latest MIOS and then the latest sammichFM firmware to be on the safe side)

- you have the 165s and 595s mixed up

- you installed the resistor networks the wrong way around (make sure the dot on the network aligns with the dot on the silkscreen)

 

none of it, actually, I found a big(ger than it should be) blob of solder on on IC1 pin 3 (causing a short to Vcc) :no: Removing it helped, obviously  :rolleyes:

 

Thanks anyway, cheers!

[nILS]

Well, a bridge does make it behave like any of the above :-)