Regarding registering to the network

Hi,
i am using Q24 series ,it is working fine in India with both wavecom EVM and the PCB design by me.
but when i am trying the same in US (new jersey) (I have selected US frequency band ) the Modem connects to the network in wavecom EVM but does not connect when the same module when connected to my PCB board. i have tried all the way but it is not registring to the network, but same module connected to the wavecom EVM it works fine.
pls suggest any solution.

Regards
Sunil Joshi

How is your signal strength?

Does your pcb include antenna conections and/or the antenna itself?
Maybe the antenna is not suited for the US frequencies?

Check your power supplies!

After start-up, registering to the network is the first thing that actually requires the module to transmit. If your power supplies are not quite right, everything can seem fine up to that point - but the real test is whether the supplies are man enough for transmitting.

Get your scope on the module’s supply pin, and look carefully - especially during the Tx bursts…

I am using quad band external antenna .with this antenna when connected to the wavecom EVM the signal strength is 30.
the same external antenna i have connected to the MY PCB and this antenna works fine with wavecom pug and play modem in US.

The power supply i am using 1s 3.8V/3A and the same PCB board is working fine when used in india.

Tha sim card what you using is india simcard ?
Wavecom module has quard band 900/800/1900 mhz probably 1900mhz suits in america, plz try by changing to this frequency