So, my modules arrived as well
Nice touch with including the desoldered LEDs
To be honest, I am now seriously thinking if I was maybe a bit over confident :p There are quite a few parts on that module that will be finnicky to solder, considering that my SMT experience is limited to SO packages and 0805...
Well, I have a decent loupe... We will see
Anyway, a quick optical check of the two modules showed something that I find odd, but I do not have much experience with bigger manufacturing batches.
What I saw is that the two PCBs are slightly different.
One PCB has two tiny holes, one beneath the power connector, the other one near the female pin header. Both very close to the board edge. That same board also has what, without magnification, looks like a tiny via. Looking at it closer reveals a tiny hole in the ground plane, where the solder resist bulges just a little bit, making it look like a via.
Additionally there is also what looks like strike damage, as if something sharp punched a small hole into the ground plane, in the area between the two heatsink screws. There is another small spot with a hole in the resist as well. Both of those could of course be transport damage.
And finally, looking at the vias of that board shows a worse consistency of the tenting.
The other board also has at least one small hole in the ground plane, at a similar location as the first one, but not on the exact same location. So whatever caused the holes seems to be somewhat random.
I assume that boards like these would be fully electrically tested? Otherwise, should whatever caused the holes have hit a trace, might that be a reason why the modules do not work?
I will try to capture a proper image of those holes. If I manage to do that I will post them here this evening.