I have a 6620 bought new unlocked ATTWS branded from ebay Phone seems to work ok, on cingular network except a problem which just suddenly cropped up with no speakerphone and no audible ring. I go poking around online and hear about firmware. I hit code *#0000# and My 6620 has V 2.14.1 28-06-04 NHL-12
I glean from my poking around on the net that I am running what, the equivalent of windows 3.0?? My question...how do i upgrade the firmware? I have seen that options are to: take it to a cingular store, send it to nokia, do it myself with a data cable... A knowledgeable answer would be welcome... Thanks...
Don't know if you still need the information but found what looks like a good source. www.iunlock.com. Haven't used them yet but will flash a 6620 up to version 4.22.1 for $30 and can unlock it for another $10.
You'd need some very pricey hardware to be able to flash your phone yourself. Also, the Nokia firmware files aren't available legally to the general public. You'd need to take your phone to a local Nokia authorized service center, or some other phone shop that offers flash update services.
For what it's worth, I have the same version firmware on my phone, with a Cingular 64k SIM, and I haven't had a single issue. Your problem might be elsewhere.