CVpal troubleshooting

This discussion was created from comments split from: CVpal kits, pioneers run.

Hi - I just finished building the CV Pal kit - my first ever (my first ever soldering really…gasp…)
Amazed to see the LED light when a USB cable was plugged in. I am working with Pro Tools 8 - the CV Pal is being recognized and I am getting stuff from the Gate outputs - but nothing from the CV outputs. Any clues why this might be?

Could you post a photo of your board? (components side and solder side).

Maybe there’s a bad solder joint on the DAC (ground pin?)

Yup - I’ll get on it…

Olivier - please forgive my nightmare soldering…
I need to buy better solder and a better soldering iron
Now you can see why I’m surprised it works at all…

Resolder the 8 pins of the DAC (part labelled MCP 4822) IC socket. Resolder the four 220 ohm resistors under the DAC.

Good solder joints look like little mountains

The ones you did for the 14 pin IC socket look OK. Try to make all the others look like that!

Thank you - I will do my best! I will also investigate smaller gauge solder! I think that might help…

Hi - I re-soldered what you asked me to - this time I bought finer solder wire and a magnifying glass with clips…
All those solder joints are much better and cleaner than before, but I still have the same problem - nothing outputs from Out 1 & Out 2. What to do next?

You can start by resoldering everything. Do you have a multimeter?

Yes, I do now…
How do I test for continuity? This is all very new…! Do I have to be able to read a schematic? I’m a little out of my depth!
I will re-solder everything and get back to you…

Thanks

Your meter has to have a continuity mode, usually denoted by something like a diode symbol, or a note symbol (it will be the smallest amount of symbols on the whole dial).

Otherwise, set it to a low ohm range, like 200ohm, and see if there is less than 10ohms resistance between the points you are measuring… :slight_smile:

Thanks!

Hi - I re-soldered everything. All the joints look good. Now Pro Tools isn’t even recognizing the CV Pal, which it did before…

The led still lights, so USB power is still getting to it, nothing else works…

Bad USB Cable - now I’m back to where I was before. Recognized by Pro Tools, only Gates 1 & 2 working…

So…what do I do now???

Send me a message, I could try sending you another DAC.

One of the solder joints on the crystal (the bottom one in the image) ?

If your CV pal does nothing at all, either the crystal or its two capacitors might be the issue.

Hi Olivier, i just build my kit today, and i only have the led light working, CVpal isn’t recognized by my laptop and my ipad.
do you have any ideas ? (I double check with some friends, all seem to be fine…)

I would resolder C2 (looks like a bad solder joint).