Errors in changing SIMCOM sim900A firmware
Actually 2 months ago, I have been working on a brand new GSM modem SIM900A having the firmware of SIM900, it worked fine.
Your suggestion worked Mr. ExperimenterUK. I tried the same thing with different USB-to-Serial cable and another PC and then successfully changed the firmware of my sim900A.
Thank you so much for the help.
Glad to hear it worked