favebook brought up a very good point, just for everybody's information, the heatsinks that usually fall are the once that are directly on top of the chips ( the bigger ones), if you take out 2 heatsinks placed in the opposite direction of one another, one will have the asic chip below it, another will be "empty", however, without totally negating the effect of positioning the miner in a horizontal position, it's safe to assume that unless you can do it easily [1] it's really not worth the effort, there isn't much you can do about these heatsinks until they fall, sadly.

[1]- if you use spilt-room design as I do and you have already made a whole to fit the miner vertically, going horizontal is a lot of effort, which IMO not worth it given the little advantages you get from this, but if it's a matter of simply repositioning the miner in 30-60 seconds, go ahead, you lose nothing.



Had to go from f to c (apparently what 99% of human beings use  ) and it turns out to be 196 c, please DON"T do that, the chips and most other components will most likely rest in peace when they are put in that temp for 10 mins, your method could have probably fixed the soldering problem but created a far greater issue.

 I suggest to simply apply some pressure on the heatsinks see which one falls, try to soldier it or do as The_binary_Observer suggested.