I have brought a amazon firestick4k....but i cannot get it to work on my samsung tv model PS43D450A2W...i can get to detect firestick,but then it comes up anynet and wont connect
I have a samsung TV that and I have a firestick that is also 4k. No issues and bought mine last year.
Maybe reset your TV and try again or reset the firestick and see if that works. I advise you contact Amazon customer service and see if they can help you.
