Xperia Z1 c6903 i can't repair with PCC error 302

[joreargento]

Somebody know solution this error, my win is win 8 pro. I've installed Xperifirm 4.7.2 and Flashtool 0.9.18.6, i think no problem in usb driver, because i can install any firmware. I installed to test various firmware (eg US and EURO) , causing IMAI and baseband stay in unknown in device.
I am in Argentina my device is c6903. Which firmware i must install? for recovery IMEI and baseband? because I cant find in the Xperifirm ftf belonging to this country, you may need to install another country and then stepping borrar firmware without baseband?
Thanks.

[joreargento]

I am in Argentina whit GSM 850/1900 HSDPA 850/1900 i have consider MENA Latin? or United states wich have a same band?

[Uliwooly]

@joreargento

Get North America's version.

[joreargento]

@uliwooly 

North American version of firmware? which is in image for c6916?

or North American version of PCC? what is the link?

[Uliwooly]

@joreargento

C6906 

[joreargento]

 @uliwooly If this, as the probe and did not recognize my IMEI or baseband:

C6906_Customized US_1276-7484_14.5.A.0.270_R1D... Although I do not remember if I flash my device as c6906 or c6903, influence anything?

[Uliwooly]

@joreargento

Did you unlocked the bootloader? did you flashed a custom ROM? I'm a bit confused on what you've done and what you are trying to do.

[joreargento]

@uliwooly I have not unlocked the bootloader, is it necessary?He was just loading custom ROM XperiFirm downs with the phone. What I'm trying to make is that a cell Z1 c6903 purchased in China (cargdo with Andrid 4.3 Comp 14.2.A.1.136 not to where it was customized) operate in Argentina.

[Uliwooly]

@joreargento

I get it, that's not going to work, you can't change the frequencies, you are trying to change the 3G or 4G frequencies correct?

[joreargento]

@uliwooly Right, I think in China customized ROM european working on other frequencies position and wanted to change the 850/1900 frequencies used for GSM and 3G in my country, I thought that changing the firmware could be achieved after all the c6903 according gsmarena supports these frequencies.
I did not consider unlock the bootloader, now I'm reading in question (http://developer.sonymobile.com/unlockbootloader/unlock-yourboot-loader/), running it you believe that I can load a firmware with the appropriate frequency like USA?