Sometimes the holes for the springs are just a bit too small for the spring ends, so I've sometimes had to drill out the holes. But you can often just tap them in lightly with a hammer. After that it's down to spring tension. They look a bit saggy to me, so if you can screw the claw in a bit more, that should help. A bit. but not so much so they pull the rear of the trem upwards. The block wants to be quite deep so that it stops the trem block moving both backwards and forwards. You van always wedge in front of the block as well if you want it nice and solid.

Just double check that you haven't got the volume control turned down or the amp volume off. I've done that before!

Otherwise it's probably a signal wire touching the grounded shielding. Easy to do, especially if you've shielded the output jack cavity where the tip spring gets pushed out by the jack and makes contact with the shielding.