MC8780 reconnection issue


The company that I am currently working for has bought several Sierra MC8780 modems and discovered a bug with one of them.

The details are the following:
Manufacturer: Sierra Wireless, Inc.
Model: MC8780
Revision: F1_2_3_15AP

The modem appears to be a refurbished one. The issue appears when the modem cannot establish a connection for a long period of time (more than 2 hours) because it is isolated with no coverage.
The modem stops responding AT commands and is unable to reconnect, even if coverage is available again.
The only way to make it work again is to power cycle the machine where it is installed.

Is anybody aware of this issue?
Is there a way to identify other items of this product that may experience the same behavior? (i.e. by serial number, etc.)

Many thanks,


It looks strangeā€¦ other modems are working fine in the same condition??