Alstaden Schematic?
Re: Alstaden Build
Hi friends: After what I felt was a pretty straight-forward build (Jacks, Pots, Sliders, Switches), I got magic smoke at CAL_SHAPE_2A during testing. Im not seeing shorts or bridging on immediate inspection and SMD was pre-populated so Im not sure where to go without a schematic.
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Hey Brian, The area around CAL_SHAPE_2A definitely looks damaged. Good to know you've already checked the power header for shorts.
CAL_SHAPE_2A is a 10k trimmer connected between +12V and -12V, so it should not get hot under normal operating conditions.
I'd suggest checking a few more things:
Check the resistance across the two outer terminals of CAL_SHAPE_2A. It should be approximately 10k. Compare it with CAL_SHAPE_1A, which uses an identical trimmer arrangement.
I'd also recommend thoroughly cleaning the PCB with isopropyl alcohol and a soft brush to remove any flux residue or solder debris, especially around the power header and CAL_SHAPE_2A. Avoid getting IPA inside the pots, sliders, and trimmers, and let everything dry completely before further testing.
I also noticed something suspicious around D16/D17. It looks like a scratch or possibly an unintended solder connection. Could you inspect that area closely and check for damaged traces or shorts with a multimeter?
Since CAL_SHAPE_2A appears to have suffered significant heat damage, it will most likely need replacing. The PCB underneath should also be inspected for damaged traces or carbonized material. After desoldering, check for shorts again! I might be a connection underneath the trimmer.
Please don't power up the module again until we've identified the cause.
Cheers,
Stefan