Factory Reset for the RC7620

I want to do the Factory Reset for the RC7620 how to perform on this

Thanks and Regards

Manju

have you tried AT&F and AT!RMARESET command?

I Have tried but it is giving error
AT&F
OK
AT!RMARESET
ERROR
at!entercnd=“a710”
OK
AT!RMARESET
ERROR
AT!RMARESET
ERROR

Thanks

Manju