Midiboy troubleshooting

Last night I assembled a Midiboy which booted correctly to the Blokas logo screen on power-on.
However, this morning, when I tried to boot it up, the screen would not power on. Midiboy doesn’t show up on computer either.

My question is: Which solder points would be suitable for diagnostic purposes with a multimeter (and which voltages should be visible across them)? Although my soldering is far from perfect I can’t see any obvious mistakes in the assembly.

I have already tried a fresh battery so the obvious reason has been ruled out.

Maybe take a close photo to check?

I tried that. I can’t spot anything that would be a likely cause. Maybe I’ll just go through each solder point with the soldering iron hoping that something might connect better.

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That’s a good plan :wink:

About the photo I ended not very specific; take some photos and upload to the forum, someone might help?

See the schematics here: https://github.com/BlokasLabs/Midiboy-Schematics/blob/master/Midiboy.pdf

You may see the pin numbers and the signals on those pins, so the first thing would be to make sure the 5V is available to the MCU.

Essential parts for USB communication to happen are the diodes and resistors on the USB data lines, and the crystal oscillator on PB6 and PB7 with its capacitors.

When powering on, hold the B button, so it enters the bootloader. If it does, you should see the device recognized by your computer.

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