Be careful with F or C. One will have your chips sitting in a pile in the bottom of the oven.
Pretty sure thats in F. But i'd still like more information on this. I'm not going to slap my S5 blade in an oven because someone told me to before properly understanding the risk even though i understand the concept.
Yep. Solder melts at 180-190C.
What you're doing here is if there are any stress-fractures in the solder which are causing issues, you are hoping the solder will melt just a little and reform a good joint. It's not a great way to do it but it's cheap.
Personally I would first inspect all solder joints with a magnifying glass. These joints can sometimes be seen. Additionally, it looks like most of the joints are accessible so you possibly could attempt this with just a soldering iron.
Personally, I'm a bit skeptical given that the chips are reporting good but I don't know enough to speak with confidence and someone else is reporting that the reflow worked for him. If nothing else seems to help though...
Edit: Just went back and saw it reported --- when run in tandem so I'm no longer very skeptical.