T-Mobile sidekick II keeps resetting

I had this problem with a new phone, and T-mobile gave me the following instructions.

Try this first:
1) Turn on phone with SIM chip in it.
2)hold down the "@" + "1" + "0" down simultaneously until phone turns off, then back on again. This should fix the problem. otherwise try this,

1) remove battery and SIM.

2) press and hold down the "w" key, and while holding it down insert the battery only.

3)A little face will appear on the screen, then a reboot button. Press the reboot button. Once the phone reboots, insert the SIM. One of those two should fix the problem.