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Unlocking a Novatel Merlin U530 under Linux

Or another reason why I am glad that I don't use 3 anymore.

I should have posted this some time ago, but forgot and so it has been sitting in my Drivel drafts folder for a bit.

You might want to try these instructions under windows too, if you get a dud unlock. Just use another terminal emulator instead of minicom.

Skip the history and read how to unlock it

I recently switched from 3 mobile to virgin for my UMTS data. I already had a Novatel Merlin U530 card from three. The card isn't fantastic but it works pretty well at upto 384/64Kbps which is good enough for mail and feed reading (my main 2 activities on the train) or ssh.

When trying to get the card unlocked, 3 was less than helpful initially, which is pretty normal for them. Initially the operator told me that my card could not be unlocked, when I asked why I was told it was in my contract. When I read the contract I had signed to the operator I was put on hold. She came back and told me that it couldn't be unlocked, I told her it could as I had read online that it could. Then I hear in the background "just keep telling him it can't be unlocked". When I asked to speak to the person in the background telling her what to say she told me that there was no one telling her what to say. I told her I could hear the guy and that I wanted to either speak to the person or get their name so it could be included in a report to the TIO. I was again put on hold. About 1 minute later I was told that I would be transferred to data services.

After spending a little while on hold I got to speak to someone in data services. First they wanted to know why I wanted my card unlocked, I explained I could get a better deal elsewhere, to which the response was that I could talk to sales to see if there were any new offers available - I declined. Next I had to play 20 questions to make sure I was the account holder and that I was out of contract. After reading the IMEI code off the bottom of the card I was given the unlock code and told that I would be emailed the software - a zip file containing some Windows only application.

I had my content filtering too high so amavis bounced the message the first time. When I rung 3 back, at first 3 told me that I need to talk to my ISP as it was very strange that the message was bounced, I told them I would just use another account - my gmail account. The guy then told me that gmail bounces their messages, so we used my hotmail account.

So now I had the software, so I tried using XP under qemu to talk to the card for the unlocking, no luck. A few days later I borrowed a XP laptop from a friend. By now I had misplaced the unlock code. Back on the 3 merri go round, this time data services was happy to hand over the code. The operator waited on hold while I unlocked the card. I started the application, inserted the card, plugged in the unlock code and got the message confirming that the card was unlocked.

Later that day I tried using a vodafone SIM, no go. Another vodafone SIM no go. My Virgin SIM didn't work either. I tried using the unlock software which kept on erroring.

I thought going to a 3 store might get it fixed quickly. Basically I was told that as the card was out of warranty and I wasn't using a 3 SIM they wouldn't provide any support. The best I could do was pay for a firmware reload from a non authorised service centre.

Back to the 3 call centre merry-go-round. I explained that I was extremely close to lodging a TIO or Consumer Affairs complaint as the card useless and not working as advertised. I spoke to a helpful operator who told me he would escalate the job.

Over the weekend I spent a fair bit of time searching for answers. Eventually I ended up finding a list of AT+C modem commands. In the list was


which is for facility lock. I played with it a bit and found that network personalisation was still active, but no other locks were on. This seemed strange to me. I figured this is where my problem was.

This is how I unlocked my card. You must have a 3 (or locking carrier) SIM inserted in the card while attempting this.

I connected to the card using minicom by running the following in a terminal (I didn't need to be root).

minicom /dev/ttyS2
Minicom should then load and output something similar to this
Welcome to minicom 2.2

Compiled on Mar  7 2007, 15:10:03.
Port /dev/ttyS2

               Press CTRL-A Z for help on special keys
AT S7=45 S0=0 L1 V1 X4 &c1 E1 Q0                     

I then entered


which should return

+CLCK: ("AB","AC","AG","AI","AO","IR","OI","OX","PN","SC")


This is a list of locks available on the card.

Enter the following


Which means, for network personalisation (PN), query the status (2), which should output

+CLCK: 1


The 1 indicates locked.

You will need your unlock code from your carrier - I do not know how to get it other than via your carrier. This is not a "how to unlock your card with the unlock code" howto. So replace <CODE> with your unlock code.


The 0 is for unlock. If it works should get OK or something, I forget exactly the response, but ERROR means it failed.

Now your card is unlocked and should work with any carrier.

Use [ctrl] x to quit minicom.


If you need the settings details for using a Merlin U530 with Virgin Mobile in Australia under Linux try the following