RF modules from Hong Kong

Following on from this:- https://www.electro-tech-online.com/threads/ic-components-limited-in-hong-kong.161552/

The components that I bought were Telit GE865 GSM modules, and they worked fine.

A few years later, a second batch appears to be counterfeits. The serial number isn't the right format to be an IMEI, and the RF shielding on the top is one piece, while the previous ones had an open topped frame and a separate metal lid pushed onto the frame.

I've opened one up and it seems to have all the right components in there. However I can't see the multiple vias on the ground plane that the genuine one has, although that could be differences in PCB process, and there are differences in layout, but I don't know how many different versions there were in the genuine ones.

As for how the counterfeit ones behave, I've only tried one so far and it turns on and responds to AT commands, but it just reports a string of zeros as the IMEI. It won't connect to the network and it won't tell me the serial number of the SIM connected to it. I have flashed the latest Telit software to it, and it reports the software version number correctly, but no change in behaviour.

The physical changes I recognize as normal cost reductions. The IMEI and AT response is curious and I wonder what their email support response was.

Tony Stewart said:

The physical changes I recognize as normal cost reductions. The IMEI and AT response is curious and I wonder what their email support response was.

Click to expand...

The date code is older than ones that I have seen before. However I know that these modules have been made in several different countries, so there will have been multiple minor changes in design.

Do you think that I should ask Telit? The modules haven't been made for some years, so I've been buying old stock.

I would assume that Telit would just say that they are counterfeit. I noticed the physical and marking differences as soon as I looked at them.