Quote from: Phoenix1969 on December 07, 2013, 04:03:41 PM

Hey Cypher... You can actually lower the cooling tower fan, the top of the plastic holder case will easily slide in between the fins, and it will cool dramatically better..... the lower you put it, the better it will cool

I remember reading about this trick before in this thread. I will try next time I move them.

Quote from: Puppet on December 07, 2013, 04:19:35 PM

Is the heatspreader of the chip still flat? If the cooler was actually damaged while mounted, its reasonable to assume the flimsy alu heatspreader got dented or slightly bent too. Its even possible the heatspreader is no longer making proper contact with (all) the dies. I once had that with an AMD CPU, no matter what cooler I put on it, it would overheat, badly. removing the alu heatspreader solved that. Not sure Id be so brave with such an expensive miner where there are 4 seperate dies under the heatspreader, but I wouldnt mind seeing the pics if you decide to try

The top of the ASIC chip looks completely flat with no damage. It was the heatsink base that was damaged as each pipe was on a slighty different level, so the total surface wasn't flat.
I changed it with a brand new heatsink and temps didn't improve, but I think the problem might be the spacers as suggested below.

Quote from: rolling on December 07, 2013, 04:30:19 PM

Some of the spacers between the aluminum bar and the board prevent the heatsink from making good contact with the chip. If you twist the heat sink from the top and it moves easily, then it is too loose. I had to remove the spacers on a couple of boards that were hot. Just make sure you don't over-tighten the screws once the spacers are removed.

When I twist it it moves but for a different reason: the screws that go through the custom made plank and the original plank are smaller than the holes, so there is a slight horizontal wobble.
Next time I switch it off I will remove the spacer or put shorter ones (plastic ones that came with the heatsink).

Quote from: RickJamesBTC on December 07, 2013, 06:23:32 PM

Cyper, I don't think blowing across the unit will make a big difference if you close the case. Right now you are bringing fresh air onto that board. Why don't you just strap that fan onto the heatsink on the open side working with the other fan, or switch the location of that board to one of the front slots where they get cold air from the big fans on the front. Otherwise, you could always cut a big hole on the side of the case and mount it properly.

Exactly. If I close the case the back of the side fan will be next to the inside of the aluminium panel, so not enough room to gasp for fresh air.
Do you mean to create a push pull configuration?
From what I see the chip heatspeader doesn't get adequately cooled - probably because of poor contact with the heatsink base or maybe it is way too hot.
I will try all the tricks mentioned here and report back.