While cleaning up my computer room I ran across an old cell phone that had quit working. It got wet a few years ago on a camping trip when my tent leaked during a rain storm. I tried all the tricks like leaving it in the oven with just the pilot light to help dry it out, but even after a few weeks it still wouldn’t work so I gave up on it. Well, just for fun, I stuck the battery in and it powered right up and said “insert sim card”. I tried plugging in the sim card from my current cell, but since I’ve since changed from T-mobile to AT&T I just got a message about the phone being locked and wanted me to enter an unlock code. So, this started my journey to see if I could unlock it without spending any money.
A quick google for “unlock cell phone” or anything like that will return pages and pages of sites wanting to charge you $10 – $20 to unlock your phone. Mixed in with those are several forum sites where someone posts their IMEI # and someone else replies with an unlock code. Well, since I wasn’t using this phone I didn’t want to pay to unlock it, and I also didn’t want to post the IMEI on a public forum. I thought, if there are so many people who are able to do this, it can’t be that hard so there has to be a way to do it myself.
After some more googling I found out that for each type of phone there is an algorithym that is ran against the IMEI # for the specific phone to generate an unlock code. Some carriers would give you this code for free just for asking and T-mobile is one of those carriers, but since I’m not a current customer I doubted they would help me, but I kept that in mind as a last resort. (I have actually used this method in the past to unlock a phone. I was leaving the country and wanted to purchase a local prepaid sim while I was there and T-mobile was very helpfull in unlocking it.) I also read about some applications you could download to generate unlock codes and possible use a cable to connect to the phone to unlock it somehow.
My next step was to try and track down one of these applications to see how they work. I checked usnet and some torrent sites and found a program called nokiafree (this is a nokia phone). I tried downloading this from various sources and it was generally just a virus of trojan. I googled for it and found the site it came from unlock.nokiafree.org. They have an online calculator and also the program you can download to generate unlock codes. I decided to try their online service first since I didn’t have anything to lose.
They have four fields to fill in,
IMEI which I got from my phone.
Network – I selected USA – T-Mobile
GEN – I selected T-mobile
Nokia Model – I selected Nokia 3200 (my phone model is 3220b and this was the closest)
Then I clicked the button to generate the DCT4 code (whatever that means) and it spit out 7 codes to enter. I wasn’t sure which one to use and they warned that after entering 3 or 5 codes it might brick your phone, so I guess be careful if you’re trying this.
Their instructions were to power on the phone without a sim and enter the code, but I couldn’t get this to do anything. If I used my AT&T sim I would get an option to enter an unlock code, so I picked the first number and punched it in, clicked unlock and presto, it worked.
I tried making a phone call on it and it seems the microphone may be too quiet. I’ll try it again and see what happens. I can also get my old address book off of it which is also a bonus.
Update: I just used this process to unlock another phone, a Nokia 3595. It worked first try.