Advice Req. Make a US T-mobile work in Australia?

[LeapingLee]

Hi, I have aquired a T-mobile from the U.S.
Before attempting to re-flash it to get it to work in Australia I just want some advice that I am about to do the right thing...
Here are its specs:-

Branded T-Mobile
ROM v 3.08.10ENG
Radio v 6.02
Model PW10B1

After some reading of these forums I have concluded it must be a 900/1900 GSM device, and it appears to be SIM locked.
(Here in Aus. we have a 900/1800 GSM system).

I intend to use a cooked rom from jeffs site to upgrade the rom.
Does the rom I use have to be one of the T-Mobile US roms ?

I realise that i wont have 1800 coverage. But will 900 still work?

Anyway, because of the sim lock I intend to proceed with a rom update.
I intend to:
Backup rom using SD card method
Download a V4.xxx T-mobile US cooked rom
Update rom using USB method

Any comments/advice appreciated (any local experience here?)

Regards from DownUnder.

[ntabikha]

well first off... i suggest you upgrade to Special rom 1.2 first.
that one will unlock your pda, so you can use it anywhere.

and about band... i'm sure i saw 1800 in the bootloader!
but not sure if you select it as default if it will carry over to the os
maybe worth a try.

in any case, if you back up your os onto SD, you have nothing to fear.

i say best thing to do, is copy that O2 os & radio (if you're sure u'll never leave australia, i dont think radios can be manipulated that often)

but dont take my word for it. wait for a confirmed user. if your not advanturous ;)

Good Luck!

[LeapingLee]

Yep, I backed up and upgraded to SE v1.2 rom using the SD card/OSImagetool method.
SIM unlocked ok
Phone works if 900mhz band is selected.
Its now thinks it's a model PW10A1.
Radio is still the 6.02 version. (B ver. )
Not sure what the consequences of this are.
Im not sure if i would benefit from a radio upgrade or not.
If I understand this correctly, I can ONLY upgrade the radio to the T-Mobile US versions, because the radio hardware is B version.
I think I will leave it like this for a while, see how it go's.
Anybody have any experience with using a B (US)version radio in a A Ver.(euro/asian) area.??

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Thanks for the advice ntabikha and THANK YOU to the XDA Developers team. :D