Signal Drops then NO SERVICE then Invalid SIM Error

[Ramasubramanian]

Dear All,
Could any one help on this issue...

When I enable 3G network service, the signal slowly drops (when I am in EDGE network the signal is full), then at one point it completely drops and one bar alone is there and in a minute that too goes off and says "NO SERVICE" and after a minute it says "NO SIM CARD".
To over come the problem I have to reboot the phone every time...
When I see it is going to 1 bar, I will disable the 3G network and within a minute it gains the signal...

My observation :
The problem is coming only when I enable the 3G network service.. today I restarted around 4 to 5 times :-(..

Could anyone help to over come this problem... Given my device information...

Device : Iphone 4 (Locked to AT&T)
Firmware : 4.3.1
Baseband : 1.59
Jailbroken : Yes (unlocked through ultrasn0w 1.2.1)

[aijay]

Dear All,
Could any one help on this issue...

When I enable 3G network service, the signal slowly drops (when I am in EDGE network the signal is full), then at one point it completely drops and one bar alone is there and in a minute that too goes off and says "NO SERVICE" and after a minute it says "NO SIM CARD".
To over come the problem I have to reboot the phone every time...
When I see it is going to 1 bar, I will disable the 3G network and within a minute it gains the signal...

My observation :
The problem is coming only when I enable the 3G network service.. today I restarted around 4 to 5 times :-(..

Could anyone help to over come this problem... Given my device information...

Device : Iphone 4 (Locked to AT&T)
Firmware : 4.3.1
Baseband : 1.59
Jailbroken : Yes (unlocked through ultrasn0w 1.2.1)

I've read from another post that 3G should be disabled if you are using it on another carrier. Hope this helps.

[Ramasubramanian]

3G is working for some hours suddenly the signal completely drops and says No Service..