I use my Jally as a 'lotto ticket'. mining solo when my gaming PC is on, and it has always run @ 60 C.
A friend bought a Jally recently to learn the basics of mining, we know they will never get ROI, and when it arrived the heatsink was loose. He removed and regooped the heatsink and after firing it up it ran at ~40 C.
Being impresseed, I pulled my Jally apprat last night. Much to my horror, the OEM heat transfer compund was a pre-fabed piece of double sided goop tape. I replaced it with some thermalake goop.
Now my Jally runs at a constant 41 C, down 20 C compared to OEM.
Moral of the story, regoop all your BFL gear to save heatstress. Note: I have had 2 replacements under warranty because of heat failures.
good advice and replacing the fans is well worth it to. replaced my fans after having them running at night and its so much better with the new fans cooler more aireflow and alot less noise
