I am using a L96-M33 module with internal antenna on a project with a few hundred pieces manufatured in last few years.
In time I figured out that some pieces (cca 5%) has a very poor reception (receiving only 1-3 satellites with under open sky, no fix after 30+ minutes), whether other ones works flawlessly.
I followed all the electrical and mechanical recommendations in “Quectel_L96_Hardware_Design_V1.3.pdf”, after all the first few flawless batches are proof enough that the layout and SW is up to spec.
Lately with the last batch (manufatured Q1/Q2 2022) there are mostly the problematic modules having a very poor performance.
All L96-M33 modules versions share marking “Q1-A2545”, although some have a better quality laser engraving, other ones a less focused one.
There are versions “AXN_5.1.6_3333_18060500” and “AXN_5.10_3333_17102400”.
Some has a FW “L96NR01A03S” and other ones “L96NR01A02S”.
The FW does not seem to have an effect on the performance.
The behavior of the “bad” pieces matches the one already described in L96-m33 do not receive any satellite
Are there any known marks of a batch with poor performance or a way to fix it (eg. integrated antenna replacement) ?