Welcome to the forum Daniel, you'll find the members on here are a friendly and helpful bunch :)
I can't say I've come across this whilst being on the forum but it sounds like the s4 would be in good hands as you're a technician by trade. I'd never try and tell you what to do as you are more experienced than I but I'd say the head needs to come off to see the full extent of the damage.
Cheers
Steve