3G restore question???

[bldblu]

Hello all,

Im sorry to post again,,but I need 1 more question answered. If I want to figure out if my iphone problems are hardware related,or jailbreak issues,,Can you restore a unlocked iphone without damaging it? i know you can restore a jailbroken phone through itunes,,but I need to restore to original condition,,and then see if everything works,,if it does,,then ill jailbreak and unlock a second time

Thx in advance

As of right now,,my iphone is 3.0,and baseband 04.26.08,,but I need to confirm either jailbreaking/unlocking caused the problems,,or if I just got a bad iphone,,period ( hardware related )

 

[bldblu]

also ,If I do the shift/restore in itunes,,then select firmware 3.0,,do i need to take the tmobile sim card out during the restore?