If the stick is getting very hot, you should put a fan to it.
I have a fan on it already. I am unsure as to if the heat sink is working properly :| What about the light and Core V dropping to 0?
Check the screws at the heatsink! Maybe they will get loose or they get stretched by heat. Its a cooling pad under the heatsink, not paste like the originals. My bitshopper-Stick has the same problems with heat and dropping VCore but i havn't the time to sort it out yet. Maybe you get the clou ...