Yes, the things you need to look for are listed in the tutorial below, along with a few other things that didn’t make it into that one, but are scattered among the other tutorials below it.
That should get you started. If you created the PDF file, it should be fairly quick to spot the potential problem areas from what you did to create it.
If you didn’t create the PDF, good luck. Hardest thing to do is try to fix someone else’s work when you have no idea how they created it, or what program they used. You’re likely better off just recreating it yourself.
