Call Sellmark at (817) 225-0310.
Talk to technical support and tell them your problem - make sure to call before you fill out the form as that phone call paves the way.
They will tell you to go to www.pulsarnv.com
and fill out an RA form.
They will send you a RA number and information in an email.
Follow the instructions in the email and send it to the address in Mansfield, TX.
They will get it in, check it out and go from there, usually replacing with a newer A version.
How do I know?
My 2 1/2 year old N750 started acting up a while ago.
I called them on Wednesday of last week.
Sent it in the same day VIA USPS and since I'm in Texas, they got it the next day.
They troubleshot it on Friday.
Sent me a new N750A on Monday.
I got the new N750A yesterday via USPS.
The A version is much clearer and has some nice features that I can use.
The extra reticles are nice.