my IMEI no is valid, and i able to registered with 2g network but not able to register 3g network..and i did not try to any other 3g sim bcoz i dont have any other 3g sim..
Process to recover IMEI no.
you have to need application called QPST u can download here...
QPTS
1. Install QPST.
2. Go to all programme --> QPST-->click on QPST Configuration
3. configure port (which is ur 3g modem port) device manager -->Ports(Com and lpt)
4.Add port in QPST (3g modem port no for ex. port 6.) click on Add new port.
http://img573.imageshack.us/img573/931/95220798.jpg
5.Unchecked (show serial and usb diagnostic port only) and select your usb 3g port.
http://img836.imageshack.us/img836/4025/35458257.jpg
6.Now your modem will show on QPST
http://img718.imageshack.us/img718/329/19117847.jpg
7.Now go to start clients in QPST.
http://img199.imageshack.us/img199/1810/24150898.jpg
8. click on RF NV Item manager.
http://img255.imageshack.us/img255/3912/18161183.jpg
9.Now Rf nv item manager will appear.
http://img204.imageshack.us/img204/4671/59916007.jpg
10.Now click on setting-->comport-->select your port.
11.Now click file Menu and select read from phone.
http://img191.imageshack.us/img191/8751/90878930.jpg
12.now it will process to read nv item from usb modem
http://img829.imageshack.us/img829/629/83468475.jpg
now you will not see that item id #550(NV_UE_IMEI_I). it is not available in your modem. it is the nv item that keep your phone IMEI no.
13.now click on File menu and select Read supported RF NV items.
http://img714.imageshack.us/img714/2108/87092916.jpg
now you will see all nv item.
http://img35.imageshack.us/img35/5720/newcg.jpg
14. click on item id #550.
15. now you will see right side 9 blank input box.(mine already fill the value).
http://img692.imageshack.us/img692/4449/19508259.jpg
16.click on check box (Hex) here put your IMEI value. Not in original format. I mean for exp . your IMEI no is 344304085113367 then u enter
Example
Another Example
Note IN first box you should enter value 8. I dont know why.
IN 2nd box put first digit of your IMEI no. you should add A. for exp 3A
and in the 5th box you should enter(single Value) 6th no. of your IMEI no.
if u cant understand tell me your IMEI to me i will tell u input value
17. Now click on file menu and select write only listed item on phone.
http://img819.imageshack.us/img819/578/75803291.jpg
now u have done you job....
IMPORTANT - if you write your imei once you cant write again bcoz after that it will be write protected. so write imei very carefully.
I think so if original firmware update in modem then may be register to 3g network..
Download link is not available