restore default setting ?

Hello ,
is there a way to restore the factory setting of the modem?

Thanks ,


it’s doesn’t change the setting
it’s all the same before the reset

I have some modems that don’t connect to the my cellular network
(I have check my device\antena\SIM\another modem - they are all good and working)

this is a screenshot of what I get when i try to dial

any help will be good ,

Are you sure the command ATDT99# is correct? I couldn’t find ATDT in the AT Command user guide. The guide says to do ATD99***1#

yes ,
this is the correct command
this setting is working with the MC8790 , but I have some modem(MC8790) that doesn’t work - so I’m to understand why , and fix them.

I can see the response to your diallers AT+CPIN? request being


This means the device is SIM locked. You need a code from your operator to unlock it.

And yes, ATDT is perfectly OK although the T (for Tone dialling) doesn’t make any sense. Dropping the ***1 is also OK if you just want to connect using the default profile.

But none of this matters unless you unlock the device first.


the sim is open
when I use the same sim with another modem - it’s working .
maybe the problem is in the setting of this modem ?

Yes, the modem is locked to another SIM and/or operator. You need the PIN code from the operator that locked it. This is not your SIM PIN code. So you need to go back wherever you got this modem and ask them to unlock it for you.

I bought it from Sierra lest year
and the modem work for a 8 mounts with the same sim ,
so why it’s locked ?

and there isn’t a “format” \ default code?

thanks ,

Yes, that does sound strange. I have no explanation. But as long as the modem requests PH-NET PIN then you are not supposed to make it work without entering that code.

There are probably ways to reset the locking to factory default, but I doubt that you will get a recipe for that here. That would make the locking pretty useless, wouldn’t it?

This sounds like a warranty RMA to me. But I am not Sierra…

Thanks ,