No echo or LED activity

I got 2 brand new FXT009 og one old siemens tc35i.
Supplier sent one more after the first because we thought it was a failed modem but…

I dont get an echo in hyperterminal or any state on the LED indicator (both modems).
I took them out of the box, inserted sim card, connected cables (power messured:12v), opened a hyperterminal 115200,8,1,none,flow=hardware

There is no LED indication or any reply on AT commands.

I known that sim-card and com port is ok, because is work with the siemens tc35 modem on same mashine.

Any suggestions ?

best regards
Jan Nielsen

Hi Jan,

Its seems like a bad power supply to me. Because the LED of the FXT009 turns on (in red ; either static or blinking depending of the state) when you plug the power. Do you use a power supply adaptor provided by Sierra Wireless or another one?


Hi Thibault - and thanks for your reply

Both (brand new) powersupplys is from Sirra and I’ve messured 12v on the multiplugh.

Hello again everybody

Supplier tells me that I may be using the wrong boot sequence and should read the userguide again.
What boot sequence??

I’m using “AirLink_FXT_Series_User_Guide-Rev004.pdf”, but san’t finde anything.
Also they suggest that there may be a series of AT commands I should commit before the modem starts to reply.
What AT series??

Jan :question:


chapter 6.4 of the FXT User Guide (you have the latest version) says what I wrote before: if the LED is OFF, it means your device is OFF (or the LED is deactivated, although I doubt you deactivated it).


Yes, you are right. I can’t imagine why the LED or ECHO would be off from factory.

I tried (blindfolded, because of no echo) to turn LED on with : AT+WHCNF+1,1 (ref guide 10.1) and I’ve tried turning on echo with: ATE1
It is frustrating when my siemens modem reacts perfectly in same inviroment and with same sim-card.

Well; I’m out of time on this project. Both modems will be returned and I’ll try with another brand.

Thanks for participation.

-Jan Nielsen


have you tried to power them with another power supply?


i just find it is interesting.