That is exactly what Sprint will have you do if you call them about it. They are upgrading the towers in my area and when ever the network is there, but outside links are unavailible my phone cannot seem to restore iteself. This has happened twice now and ##72786# solved it both times.
But I also learned something this morning when I called for the second time. The first time I was in a rush and just needed to make some calls, so I did not take note of anything. Today I learned that you may be able to get your MSL from them as part of it.
Now I recently had no trouble getting my MSL from them when I called about the code required to enable "USB Charging" (which did not work BTW.) This was done after the first time I had to run the ##72786# Reset. Today when I called they told me that my phone may ask for a passcode after choosing Reset. The Rep told me the code to enter without hesitation, nkowing my MSL already,I realized that the code they gave me was my MSL.
So the point here is..Call in, tell them that you cannot make/Recieve calls or texts. When they tell you to choose reset (after entering the ## code) if they don't mention the passcode, then tell them that your phone is requesting one. And now youhave your MSL.
Or try the USB Charging thing I mentioned above.