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just want to know what people are doing about s7s with loose heat sinks. the fix seem like pretty simple to do down here with some  Arctic Silver Arctic Alumina 5g Premium Ceramic Thermal Cooling Adhesive.

what are you people doing?

thanks in advance

contact bitmaintech  and send the board in.

ask if they will  give you  a coupon to help make up for dead board.

you can sell the coupon or use it.

How much would it cost to ship back to China from South America? If its cheap then send it in.

If not just fix it yourself. You can buy high quality heatsink thermal tape and it would never fall off.

I'm basing my advice from the S7 pictures.

It's going to be a little more involved than the above advice.

1) We have no idea how good the thermally conductive tape is. Here is a datasheet for the 3M product: https://www.adafruit.com/datasheets/3m8810.PDF

a) Notice that the thermal impedance goes linearly with the tape thickness.

b) The thinner the tape the less shear force it can tolerate.


2) Here are your options:

a) Send the board back.

b) Attach the heat sink yourself:

i) If you choose to do it yourself, make sure that the chip surface and cooling fin surface are perfectly clean. The cooling fin and chip surface must be in complete and uniform contact. Use isopropyl alcohol to get rid of any finger grease and dry with a clean tissue (the ones they sell to clean glasses are fine).

ii) Make sure the fins are in line with the neighboring fins as to not obstruct the air flow.

The tricky part of this option is what kind of thermal tape to use. The most conservative option is to use the thinnest 3M thermal transfer tape and keep this board under observation to see if the cooling fin stays put.

c) Disable the offending chip.

You need some super electronics expert for this step. If they could figure out if there is a resistor that could be removed that would power down/disable the chip, this would be the fastest and best.

My concern with step b) are the reports of boards burning up because of detached cooling fins.

I would re-attach the heatsink in 1 minute. Why  should I lose time waiting for such a "broken" unit arrive to China and back?

I agree with Rabin - I'd reattach the heatsink myself using thermal epoxy as you said in the OP.

Where gravity is an issue, NEVER NEVER USE ONLY THERMAL TAPE!!! It is NOT made for structurally holding a heatsink on and if the sinks are vertical gravity/heat WILL cause them to start sliding and eventually fall off.

I would fix myself, theres a good chance of a heatsink falling off again during shipping of the replacement.

You can use this and fix it yourself. http://www.amazon.com/Arctic-Silver-Alumina-Adhesive-AATA-5G/dp/B0087X725S/ref=sr_1_2?ie=UTF8&qid=1449183502&sr=8-2&keywords=artic+silver+thermal+adhesive (http://www.amazon.com/Arctic-Silver-Alumina-Adhesive-AATA-5G/dp/B0087X725S/ref=sr_1_2?ie=UTF8&qid=1449183502&sr=8-2&keywords=artic+silver+thermal+adhesive)

Also ask before doing any in house fixes.  With their warranty anymore if you open up and attempt to fix it voids warranty.  So if they can tell you did some fix... it might cost you in long run.  But it does not hurt to ask them, they might say yes go ahead and try.  Just get it in email or ticket on permission before doing it.

But ask them what to do on it.  And Phil is right for sure ask for coupon, bitmain has been kinda stingy on coupons anymore but it's worth a shot.

there is no LONG RUN.the warranty is only 3 months, it will expire soon.
shipping to china, fixing, them shipping back to you will lose you so much more time and money as well.
just easier to fix it by yourself, or even running with only 2 boards would still be better than losing so much time/money shipping.

and the bastards at BITMAIN ... you pay like 1700 $ for such bad quality equipment with sinks that fall off and all kind of problems... they should give you a big discount coupon for sure !

I'd fix it myself - too much downtime and EXPEN$CE in shipping it back to them to fix and they WILL NOT COMPENSATE YOU.

 Bitmain warrenttee is a joke.

Just fix yourself, shipment charges ganna be so much more then the repair cost. Use tape if you have to, but make sure its the tape is not in the hot zone as it might melt.

Um, 'Not in the hot zone'?
The heatsinks being in contact with the chips sorta makes that non-sequitur as that is where majority of the heat is produced...