Did the jailbreak and now cydia wont open

We will need a bit more information, please.

As in: what iOS did you jail break, what jail break tool did you use (and did it say the jail break worked)? Also, what exactly is happening when "Cydia won't open"? Are you pressing the icon and nothing happens, or is it flashing...?

If we have more details, we can hopefully figure out what is going (or has gone) wrong. Thanks.

Marilyn

P.S. And, since you talk about a jail broken iPad, I've taken the liberty of moving your post over to the Hacking section. Thanks for your understanding.