Help S7 international SM-G930F stopped working. How to flash

Hi. This is my first post. I think I posted in wrong location. Sorry. Don't know how to move it.

I purchased my s7 here in the united states and samsung told me I have to mail it back to vietnam where it was made which I would rather not do.

Bought the phone last fall and set it up with cricket. It has been working fine until 2 weeks ago when I came back from vacation. I had very bad reception, so bad, I could not make a call without it dropping. Data and texting still worked though. Did a factory reset and had cricket check the settings and give me a new sim card. Still didn't work.

Then had at&t port my number and give me one of their sim cards. did another factory reset and had their guys check all the settings. Reception is still horrible and now texting and data won't work at all. Also the phone works intermittently. One moment call can last 2 minutes before being dropped and the next moment it says NOT REGISTERED ON NETWORK. Att said it must be the phone.

Samsung wants me to call the vietnam office and mail the phone back there which I don't want to do.

What else can I try on my own? The warranty is over in a month.

Should I try flashing it? Any help is greatly appreciated. Thanks.
Last edited: