Dead GSM4(2G) Sub-module

[rocketsimon]

My GSM4 (2G) as stopped sending SMS messages...

The UCM module seems to be OK - it is responding in Comfigurator and I've updated the firmware to the latest OK.

The SIM is OK and we are still getting 2G service in this area.

On the UCM board the Green RDY LED is on,  the BUSY1/D2 Red LED is on, and the BUSY2/D3 and ERR/D4 leds are off.

On the GSM4 sub board (with SIM900 module) the D4 red LED is lit,  and the D3 green LED blinks every few seconds.  However - relatively regularly (don't have to stand there and wait long) the D4 LED goes out for a little while,  the D3 green LED blinks about 3 times, the D4 green LED comes back on and it goes back to blinking every few seconds...

Any ideas of the problem?  Has the GSM module died?

[slychiu]

Busy1 Led permqanently on indiactes a problem with the network or dsignal. Are you sure the sim cardis active, and has money?
Can you call the gsm number, and does it answert? does athe gsm make outgoing calls?
can you test the sim card ion your phone to make sms calls?

we  dont have 2G gsm modules anymore, the replacement would be 4G/LTE (if the module is faulty)

[rocketsimon]

If you call the GSM number it rings and answers...  although nothing is heard as I've previously decommissioned the voice element just using it for SMS.  
And yes - the SIM card works on another phone to make/receive calls and send/receive SMS messages...  using just 2G.  

Thanks for the help.

Busy1 Led permqanently on indiactes a problem with the network or dsignal. Are you sure the sim cardis active, and has money?
Can you call the gsm number, and does it answert? does athe gsm make outgoing calls?
can you test the sim card ion your phone to make sms calls?

we  dont have 2G gsm modules anymore, the replacement would be 4G/LTE (if the module is faulty)

[slychiu]

It looks. like the sim card or SIM900 is faulty. If you have 4G/LTE in your area, you may have to buy  a new UCM/GSM4