Do they also stop Psychic powers from hitting the target if the roll is under their value? Doesn't really state it in the book or not just says any attack.

Thanks.

A few powers state they can't be stopped by fields (usually when they target the psyker using them!) so, presumably, all the ones that don't mention it can be blocked by fields.

Now, personally, we tend to do a bit of "common sensing" when it comes to forcefield and psychic powers. Sure, you can stop doombolts. You can't stop a psychic scream, even though the rules interestingly enough allow you to take cover from it and even dodge it (yeah we don't allow that either).

But yes, by the rules as written, any psychic power that deals damage and does not explicitly mention it's immune to fields... is not immune to fields.

Which power specifically states it bypasses fields as an example?

Boon of Tzeentch specifies it can not be blocked by a field save. It can, however, be soaked by both toughness and armor. 'Cause sense is for wusses.