Limited Service or No Service problem

[cuddlez]

SGH-D500 Orange mobile, debranded with the Debranding software as purchased here, yet with O2 I get from time to time: "Limited Service" or "No Service"

The IMEI is still original and when I type:
*#7465625# all the locks shows up as inactive

Is this a software problem or network provider problem, or is there a hidden setting that Orange have stored in the mobile, to stop people unlocking them?

[Cannonball2]

Is it a D500e or just D500. The first is quad band and the second tri band. If you flash them with wrong software they don't work properly.

[jhuds2004]

this sounds like a weak signal problem

[cuddlez]

D500 Tri-Band

I am putting it down to a weak signal, my old nokia 3410 used work alright, looks like the newer phones need a stronger signal to work.

Or is there a code to enter to boost the signal gain?