galaxy alpha 850F no network

hello guys ;

i recently bought a new galaxy alpha 850F but yesterday the phone won't connect to any network , i made some researches and i found out that my imei was changed by it self O_o for 365************* to 0049 can someone help me please i can't receive or make phone calls .

Alpha 850M vs 850F?

Hey everyone, noob here. I have an 850M on the way. I chose that over the A based on all the info posted on several threads. I was a bit concerned that the M wouldn't have all the necessary LTE bands for TMobile, however there was one thread here that clarified any doubts. After ordering the M, I saw that the 850F is available in aqua blue, very cool! It's a unique color I've never seen on any other smartphone. I really want the blue color instead of the gold version of the 850M that I ordered. I searched extensively, but can't find any definitive answer on the 850F. Some say the F is missing the 1700/2100 bands, others say it's present and works with Tmobile just fine.

Has anyone used the 850F on Tmobile, if so how are the LTE speeds? In my area, Tmobile LTE speeds are blazing fast. I consistently get 25-35 mb on an old LG G2, off peak hours I can get as high as 50-60 mb. I want to get the 850F in blue but not if it can't be LTE compatible. Any feedback or comments would be appreciated!