We used the modem wismo 218. Suddenly following problem: when connected to a PC through a program of Sierra Wireless Discovery Tool modem is registered on GSM network but through the port of UART modem information is not displayed, that is, the modem does not respond requests the host controller. In the AT commands to the modem does not respond at all, but to make a call to the modem can be. What could be the problem?
Could the situation I described happened because of the broken modem firmware WISMO?

Did you try changing the FW?


I cant change the firmware via the PC becouse port UART does not work. Is it possible to update the firmware without a PC? How to do it?