Issue with production of 6.0.0.1 in JLCPCB (?)

[germanviscuso]

Hi! I grabbed Gerber_Files.zip (also JLCPCB BOM and CPL from the same place) and ordered fullblown boards with all components in the BOM except for the Pico 2. I ordered Pico 2 from Aliexpress. I flashed the Pico 2 with the latest firmware and, in isolation, the Pico 2 are correctly Autodetected by the logic analyzer software (and always detected by my Win10 machine when I connect it to USB). After soldering to the logic analyzer PCB I connect the Pico 2 via USB-C and the Pico 2 led doesn't turn on, the board is not Autodetected and of course I cannot use it. Can anybody confirm these gerbers are fine (strangely the files inside are dated Nov 27 2024)? Can anybody suggest what could be the issue? I measured voltage on the power pins and they seem fine. I managed to get the led on and detect the board by changing the angle of the usb-c cable. But now I can't and I tried multiple usb-c cables with no luck (it's dead). Could this be a faulty Pico 2 or a bad usb-c connector on it? If yes why the Pico 2 flashes and works when not soldered to the board? Could this be a bad gerber and the one I need is actually here? Thanks!

[gusmanb]

The files inside 6.0.0.1 package are dated Feb. 01 2025:

So if the files you have sent have date from 2024 you have sent the 6.0.0.0. In any case there are no differences, only in 6.0.0.1 I included a missing edge cut file (which JLCPCB does not need), except for that and the date the files are identical:

The most probable is a short when you soldered the pico 2 or a faulty USB connector (and this is the most probable as per your test).

[germanviscuso]

Thank you gusmanb. I have isolated the issue and has nothing to do with the Gerbers (that's fine). As reference for others facing the same issue: it was excess flux that was causing sporadic shorts (even being conservative about flux, I don't use a lot). Since the Pico sits right on top of the PCB there's no way to clean flux trapped below it after soldering. I have changed my method to solder without flux and with less solder per pad. Hot air and solder paste also worked fine.