Doesn't sound like you antenna is a power antenna because you said you pulled it up. If that's true, or even if it is a power antenna:
- Sometimes something gets in between the sleeves and it wont go back down or,
- There could be a bend somewhere, or a dent, making part of the antenna stick and not fit back in.
And yes, of course if it's power make sure it's plugged in at the back.
Also, try pressing the scan button for the radio and see what it picks up, might just be the radio. Is it a new one or a used one?