What does it do? 3 things, and 3 things ONLY.
1) Programs your phone, including your MTN, MIN, and Home SID (represents where you live, and what your home switch is)
2) Downloads Preferred Roaming List, so that your phone will automatically know what network to use when you are not using your home SID.
3) (newer option) you can change your own ESN... just call it from the phone you "want to use" and tell it your phone number... pretty slick!!
Things you should and should not do:
You SHOULD; occasionally update your Preferred Roaming list, From your HOME AREA or another VZW coverage area
You SHOULD NOT; dial *228 in an extended network area. (another carrier's towers) It is totally unnecessary (and honestly a little dangerous) to do this when you reach your destination city.
About option #1....doesn't it program the phone AND update the PRL?
I update my phone about once every month, or as needed, and my PRL date will change everytime.
Very true and well said. A constantly updated PRL benefits you if you are in a fringe area where roaming is important. Anything short of that and you really are wasting your time. I think without a doubt the biggest pusher of this myth are a lot of the Verizon reps. themselves (well intentioned as they may be). They almost always direct customers to resort to updating their roaming capability regardless of what's going on. It is no where near the cure all that people have come to presume it is. It can't hurt but it is not a magic pill for most problems in the least.
The other myth that kills me is "ONLY option 2 can update the PRL" . . . Wrong! Option 1 does it as well.
I see a lot of people telling people to use *228 to fix things like glitches or software issues, and that is simply NOT TRUE. Its kind of aggravating actually since they are not clear on what it does, and simply pad their count by offering it up.
Firmware( phone flashes ) fixes are designed to resolve software related problems. With the newer phones you can do a FOTA ( Firmware Over The Air update ), phones older than 1 year most likely can't .
*228 is not a fix all as stated above and can't hurt to do it, but for certain things it is simply not applicable .
I'm not that familiar with the ins and outs of cell phone programming but I can tell you this for sure. *228 can, in effect, "add towers" and improve reception!! The town where I work just recently got a cell tower. I was able to get 1 bar of signal from a tower in the next town and sometimes, maybe, if I held my mouth just right, be able to make a call from the parking lot. After the new tower (which I can see from the building where I work) was activated, everyone started bringing their phones to work and getting new phones and talking about the new strong signal from the new tower. Meanwhile, I still had 1 bar. Inside I had no service while others had great service. I did some poking around and stumbled across the *228 Option 2 thing. So I go out in the parking lot and try it. It goes through its thing and I restart my phone. Voila, I now have full bars in the parking lot and 4-5 bars deep in the bowels of the building. So, again, this is new to me but I can say that it can absolutely help in the case of a new tower being put up. Even if Santa Clause did say so