change radio frecuency sm-a260f
I want change the radio frecuency many units of samsung sm-a260f
the phones are unlocked
when i search the carrier, can found 5 carriers, in 3 diferent basebands.
but when i put the sim card that i want, the phone are in emergency calls only.
at *#0011# i can see that my carrier is gsm1900 and the phone shows wcdma900.
i tried, selecting 2g, 3g, 4g, or auto modes,
but no way.
How can i change wcdma900 to gsm1900?