I rarely chime in on these but there is a lot of misunderstandings and misuse of terms goign on and the guy chiming in as "3rd Level Tech" has no idea what he is talking about.
"Unlocking" a phone - gsm term for unlocking a phone for use with a SIM card.
"Flashing" a phone - cdma term for programming MDN/MIN/Data settings/PRL in cdma phone for new newtwork
the pic is of an S4. many of the newer cdma (sprint and verizon) phones have SIM cards slots but on most of these phones they are for 4G Lte authentication only. A few (mostly Verizon's) are global phones and can be rooted and have the sim card unlocked for GSM carriers to varying results.
A sprint phone can be used on straight talk since they use many different types of phones.
the guys talking about the bandwidths and frequencies used by carriers....ignore that stuff (edit: it matters depending on your area and what is being used by a particular company in your area but most will work, best verification is to check with the company. a yes from them is always a yes and a no may still be a yes as far as an answer to the question will it work on that network, if you know what your doing.
I wouldnt recommend letting anyone do the flashing that requires ESN modifications and donor devices lol you know what i mean. To me this ruins both phones for most peoples future use and is a clumsy way to get onto a new newtwork
1st make sure the carrier you want can/will activate the phone.....Cricket takes any cdma. Boost/Virgin Mobile are Sprint and will not be activating any Sprint phones with a bad esn. Again, straight talk is offering BYOP on cdma and gsm phones. PagePlus is Verizon..and there are many services out there. GSM phones can be unlocked to use with other gsm carriers and data will work as long as your APN information is configured for new carrier.
1 your using a cdma phone. so "flashing" services/info are what you want to look into.
IF DIY youll need cdma tool (DFS) or CDMA workshop to program and change prl. 2 You'll need a PRL for new carrier, MSL code (getprop.ril MSL if on below 4.0.4 on the e4gt), drivers for your e4gt, and APN information
google any of the terms i mention. and the information is easily out there. you'll need to check other forums to find more info as AC does not have much on the topic or any major developers for that matter...i stopped coming around here and got into other forums because as much as i love the "android community" the people here can sometimes be well meaning enthusiast but most often are trolls screaming about how knowledgeable they are while giving misinformation to each other that can damage your phone. none of this is illegal. taking a phone you own to a new carrier that will activate it is not illegal. Flashing the phone is not hard and is a matter of having diagnostic drivers installed correctly, the correct prl and information for new carrier, and reading instructions without altering them. You're looking inthe wrong place for any information about flashing phones
If anyone needs help with flashing or rooting a phone. PM me. - thats not a sales pitch for any services or private solutions... just a neighbor offering to help free you from the Matrix