Ok so my gigabyte 1070's, less than 6 months old are starting to fail. They are gummed up with dust and one of them seized up altogether. Checked out
http://cryptomining-blog.com/8138-how-to-maintain-and-repair-dual-x-and-other-non-serviceable-gpu-fans and
https://youtu.be/Tf0FxUe30rU and decided to have a go disassembling and replacing the sleeve bearings with ball bearings.
Got the 2x5x2.5mm bearings and shims off ebay and set to work. Took all up about 5 hours! Which included going out for some superglue. The fan mounting brackets are extremely fragile to the point where a stern look is almost enough to make them crack. Also on one fan I managed to break off the metal spindle attached to the fan so superglue definitely needed!
Apart from being extremely careful the only really hard bit is separating the fan blade section from the stator. These fans are NOT meant to be disassembled! You need to apply just enough force in just the right location and pray the bits you want to separate, come apart and nothing else. There are very small bits of plastic that will break easily, not to mention the small built in circuit board which attaches to the stator coil by 3 current bearing pins. When applying separating pressure, a lot of stress is put on these pins and you are relying on the quality of the solder joints to hold them. You want the tiny plastic holding ring to give way before the solder joints do and I can tell you, they are pretty evenly matched!
Removing the fans requires separating the heatsink from the chip so the silver lining to this ordeal is that you hopefully apply better quality heatsink compound. I discovered the existing compound had lots of voids and some shiny bits of chip were visible. So hopefully my application was an improvement.
Anyway, put it back in the rig... and the middle fan not spinning. Totally free to spin but apparently no current reaching it. Ran it for 30 minutes with just the 2 adjacent fans doing the work and it seemed to run ok, without overheating. Which at least shows the upgraded fans are working way better as previously when the middle fan was seized up, the temperature soared.
I wasn't very optimistic but decided to take out the middle fan and resolder the circuit board to coil pins. Put it back and much to my surprise, all 3 fans are now working perfectly!
In theory, with the nice new ball bearings, it should run for years, long after the card ceases to be mining economic. The bearings are sealed so no matter how much dust gets thrown at it, they shouldn't seize up. In theory.
I have 23 more dusty cards running that will likely seize up in the next few months so I have 23 x 3 = 69 more fans to replace with bearings. If anyone knows of any magic special way of separating the fan blades from the stator without risking breaking anything, I would so love to hear it! Anyway worst that can happen is I break a fan that isn't working anyway so no big deal.
