Magnets fell off MK52 heatbed
Sorry for the lack of photos. Repaired and moved on.
What happened? A screw driver rolled underneath my printer. After hearing an unusally loud series of clacks, I fished out the screwdriver now covered in about 4 magnets from the bottom of the heatbed. Concerned this might be a defect affecting the whole bed, I lightly tapped the remaining magnets with that same screw driver, the red one that came with my MK2S kit, and found several others easily detaching. One set flew off the screwdriver hopskotching from magnet to magnet then flinging the cluster of 4 or 5 across the room. At this point about half of the magnets were missing from my heatbed. Prusa Support hadn't heard of this failure before but I didn't press for an RMA being in the US. I have some experience with rare earth magnets and glues so fixed the bed with no issues since.
In case any of you have this issue too, I used Loctite Stik'n Seal Extreme Conditions glue. It holds up well against bed max temperature and seems to do the job the glue from factory adhesive didn't. I've used this glue to repair minor rips in my PEI before 2.5 kit upgrade so know it can withstand 48hrs long 120°C prints perfectly. And being slightly elastic, doesn't suffer from impact forces cracking stock glue seems to fail from.
MK2S kit owner since 8/15/2017