Bitcoin Forum

Hi all, I'm trying to water cool a few S9s and I'm having some trouble.

I have a few large aluminum waterblocks that are the size of the hash boards and I'm currently laying the aluminum block on the top of the heatsinks and using thermal paste as the interface material. The problem I'm having is that when I give power to the board it doesn't start up. There's a clicking noise that sounds like a relay or a small arc striking coming from the connector side of the board. If I space the blocks away from direct contact with the heatsinks using thermal pads, the board will work, but thermal pads do not transfer heat as effectively as the paste.

I taped off the capacitors and the coil, but that didn't fix the issue. My next thought would be that one of the heatsinks is carrying current and it's being grounded by the plates. Would you guys have any insight as to if this is possible and which one I should check?

Thanks

The clicking noise might be the miner that keeps restarting/rebooting and I think it's because of the fan. The s9 miner will always scan hashboard and fans before they run but if the miner detects no fan the miner will automatically reboot/restart. That's I think the issue why you heard a clicking noise.

However, you can bypass it by flashing the miner with modded firmware like Braiins OS.

I don't know about the grounded part you mean but if you can take a picture of your miner what it looks like maybe we can find the cause of it.

I should've included that I disabled the fan check at startup using Braiins. I figured out the problem. The heatsinks are actually getting voltage in each domain and using the bare aluminum plate with thermal paste will bridge multiple domains, resulting in a short. There has to be a non electrically conductive interface between the heatsink and the cooling plate on the backside.

Braiins OS+ is not modded firmware, there is nothing from Bitmain on it. BOSminer is made from scratch (in Rust language) and doesn't behave like the predecessors it replaced. The rest of the OS is an Openwrt derivative, not that Xillinx Linux used by Bitmain and modders.

As for the heatsinks, they come separate from factory for this reason. Sharing a single plate seems challenging with blocking conductivity but not thermal transfer... Also the thermal glue/paste seems to be eaten by various synthetic mineral oil brands, so even if the tape based solution might be less efficient transferring heat, but it seems to last longer.

Not that any other cooling method is needed to cool these S9s since they run relatively cool in the worst climate, but if you insist on doing so, you should go for immersion cooling, let those hash boards swim in the non-conductive liquid, and you won't have to worry about shorting the chips.