Put sim card

You can unlock the Sidekick LX from Jamica Network digicel using the Unlock code ,you can get the Unlock code within 0 to 5 Hours(approx) you can get the code at reasonable cost here Simpleunlocking.com and Unlock it ,then you can use it with any GSM Network Sim card....Follow the instructions below and Unlock it step by step...

Sidekick LX Unlocking InstructionsWarning : Do not enter any wrong unlock codes on your Sidekick LX mobile phones. If you enter over a certain amount of wrong unlock codes on your Sidekick LX mobile phone, your phone may get hard locked and sometimes become unusable.
1. Switch ON your Sidekick LX with a Not ACCEPTED SIM Card.
2. If your Sidekick LX asks for a PIN code, then enter your SIM card PIN and press OK.
3. Sidekick LX will ask to enter an "unlock code".
4. Enter Unlock Code we send to you.
5. Your Sidekick LX is now unlocked.

*NOT ACCEPTED : We mean, to use a Sim card from a network other than the network your Sidekick LX is locked to.

It says just Network lock only,You need to enter the Code if it locked Network mean.You can get the Unlock code at here
http://www.superunlockcodes.com/sidekick-lx-2009/rs12wp9/ and Unlock it,get the Unlocking Instructions below to unlock it step by step.
Sidekick LX 2009 Unlocking InstructionsWarning : Do not enter any wrong unlock codes on your Sidekick LX 2009 mobile phones. If you enter over a certain amount of wrong unlock codes on your Sidekick LX 2009 mobile phone, your phone may get hard locked and sometimes become unusable.
1. Switch ON your Sidekick LX 2009 with a Not ACCEPTED SIM Card.
2. If your Sidekick LX 2009 asks for a PIN code, then enter your SIM card PIN and press OK.
3. Sidekick LX 2009 will ask to enter an "unlock code".
4. Enter Unlock Code we send to you.
5. Your Sidekick LX 2009 is now unlocked.

*NOT ACCEPTED : We mean, to use a Sim card from a network other than the network your Sidekick LX 2009 is locked to.
Each Sidekick LX 2009 mobile phone has an unique unlock code. You can buy the unique unlock code for your Sidekick LX 2009 mobile phone using the form above.

I just got a sidekick off the internet and I put my SIM card in the phone and it says no SIM card. What do I do? Anyway to fix whatever is wrong?

once it says to enter your "special code" you hit cancel and it enables the sim pin. then you go to change sim pin, put in your old sim pin and put in a new one. then go to network settings and select "scan and select manually". once you find at&t click done and you can use the sidekick.

under the battery slide it in

not sure if this works with the 2008 but its something you can try, i put a sim card in my LX and was asking for a special code to unlock the phone, well right now tmobile isn't unlocking the sidekick, but you can trick the phone into using the sim card. First go to your settings, go to "SIM Center" and click on disable sim lock, enter in whatever your sim password is (if you dont know your sim password get your PUK (pin unblocking key) number which customer service will give you if you call 611, you can change that SIM pin by typing **05*PUKnumber*newpin*newpin#) now if you wanted to change it to "0123" if your puk was 9483992 its 7-9 digits you would type **05*9483992*0123*0123# now your sim pin is 0123. (trying not to make this super complicated) it will say sim pin not accepted click ok, now click change sim pin you can type the same sim pin 3 times if you want, 0123 0123 0123 now at the top of the screen bars will show up with a white phone beside it, go to Settings-Network Options-Scan and Select Manually, the SIM network should come up, click ok when it finds it and it will connect, now you can call and text on whatever sim you have in the phone

just ask the phone company provider for your PUK2 AND PUK codes.
when you get them go to the jump menu dial
**05*PUK*passcode*passcode#
the passcode is any 4-8 digits you'd like, that are NOT, AND I REPEAT N - O - T consecutive.
(for example 2736 is good whereas 1234 or 9876 is bad)
if it asks your for the code again put in the PUK2 then go to settings> network options goto the "scan and select manually" button and chose your carrier.

You might have to get a new phone and sim card... 

works for sk 3, slide and lx.
the video says only at&t in the U.S. but... i've seen it work for fones in europe.
try it.

You can try this. It works on Sidekick 3's

1. at the same time hold the menu button (top left) and the jump button (bottom left)
2. This will bring you to the emergency screen (it gives you the option to make an emergency call)
3. Open to the keypad and hold in the menu+shift+q buttons at the same time.
4. The phone will reset and clear/unlock the security code

If that doesn't work you can trya Master Reset

1. Remove the battery and the SIM card from the device.
2. Flip the sidekick open; press and hold the letter 'r' on the keypad.
3. While holding the letter 'r', place the battery back in the device. DO NOT INSERT THE SIM CARD YET.
4. The sidekick will restart itself twice. Please make sure not to let the letter 'r' go until it has fully rebooted.
5. Once it has fully rebooted, remove the battery, re-insert the SIM card and battery and power up the device.
6. Once the device has fully rebooted, all prior information should be erased from the device and it should be restored back to the default factoy settings.

Thanks to Sidekickskins.net