B-Con
Thanks for the tip, Superbxxx!!
 
I just received my 780 Classy today, and...
 
Insta-rattle!!
 
In mine, the rattle was coming from the fins at each end. They would randomly rattle at various fan speeds. Luckily, I didn't need to disassemble the card. I removed the rear mounting bracket and placed a piece of folded up thermal tape under the fins. At the front of the card, I placed some thermal tape across the top of the fins that are located directly below the power connectors. The fins no longer rattle at any speed.
 
I shouldn't have this issue on a $550+ card. So, now, I just need to decide whether or not to keep the card.

Q5Grafx
I to have noticed this rattle when i added the second card in sli. My temp fix was to use a rubber o-ring in between two cards so it applies a very slight amount of pressure on the cooling housing and it worked for about 4 months. this morning the rattle came back intermittently. I will have to try your repair. I will be getting the third card for the sli setup later this month as well as the 3.5 spacing sli bridge and a third backing plate. I will do the repair then while the system is open and i have to gain access to the cards anyways. wierdness, while i was typing this note the rattle just stopped again. Thank you for your post. I will try this fix in a few weeks as a preventive measure on all three cards.
 
Thank you,
Q5Grafx

bluckshot
I'm experiencing the rattling sound from fan and coil whine when running 3dmark. Using other benchmarks aren't as bad as 3dmark, that one makes it sing. Heavenly it handles better. 
 
Going to try the screws.
Contacted tech support whom told me that it may be due to a capacitor in my PSU...Even though the first time I fired it up I was using a different PSU. They also told me to try it in a different PCIE slot. I understand why even though it's quite obvious it's coming from the GPU.
 
What does your card sound like during firestrike(?) in furmark?
 
I'm using a GTX 770 SC stock
 

bluckshot
Both of them are very tight, however I found something else, one of the metal pieces of the heatsink is loose, closest to the ports. Only one of them. 

Superbxxx

Gwiz187
When i press up against the last fin ( with a screwdriver with insulated handle ) very gently the vibration stops,not really in the mood to RMA a card and to get the same issue back so thermal tape it is.

Good luck then and keep us posted .

Superbxxx

Gwiz187

Superbxxx

Gwiz187
When i press up against the last fin ( with a screwdriver with insulated handle ) very gently the vibration stops,not really in the mood to RMA a card and to get the same issue back so thermal tape it is.

Good luck then and keep us posted .

Where do you usually buy such tape?,i can only find pads none of the hardware stores in the area have it.

I'ts a bit rare to find. But if you cant find it try it with a good electrical/insulating tape. Or try in the Ebay.

Scarlet-Tech

Gwiz187

Superbxxx

Gwiz187

Superbxxx

Gwiz187When i press up against the last fin ( with a screwdriver with insulated handle ) very gently the vibration stops,not really in the mood to RMA a card and to get the same issue back so thermal tape it is.

Good luck then and keep us posted .

Where do you usually buy such tape?,i can only find pads none of the hardware stores in the area have it.

I'ts a bit rare to find. But if you cant find it try it with a good electrical/insulating tape. Or try in the Ebay.

Well i still didn't buy it and the problem seems to be coming and going although the noise is much less now and can only be heard when i listen at the back of the case ( slight rattle ).
I'm happy with the performance of the card only i don't think i will buy anything from EVGA again or any other brand with so called  Active Cooling Xtreme,i have a XFX 6970 it's pretty loud fan wise but atleast i don't hear any mechanical issues,from browsing the forums about this issue it seems it was already reported sometime around september 2013 while i bought this GTX 770 SC ACX in november,to me not a good sign.

The funny part is someone recommended EVGA to me but i can't pass that recommendation myself.

But thanks for the help man,and when the noise really becomes annoying i will try the fix you were willing to share.

Edit: I had a laugh at the biosupdate though that was issued in the other thread..  :D,and just seeing the award specifically for the card i have for the lowest noise.

It makes you wonder while so many report problems if these awards are legitimate.

Think of the awards with logic of the rest of the world... You buy a Ferrari, and it get 5 mpg for gas, but the one they test get 17, so it gets the award for the best fuel mileage in the Ferrari line.

What every seems to think is that everyone single items coming off of every single assembly line is exactly the same. I am not saying it is fair, but severely unrealistic. Don't forget, the testers have one card, so they are awarding for that card, not for the entire line of cards. Watch the obsidian 250D reviews.. I have seen 5 so far, and two of them flat out said, this case is stupid, don't buy it... I have never seen either of those reviewers give bad feedback like that.

If a $18,000 to we'll over $1,000,000 car can come with major defects, causing it to burn to the ground, what makes people think computers parts can't? I am honestly baffled by all the whining and crying at this point. Get the *+ș( past it. RMA it or find an at home fix. If you can accept cars having problems and not a computer part, then priorities are flawed.

*not pointing the finger directly at anyone in this thread, but seriously, use some F*****G logic. *

Scarlet-Tech

chrisdglong 
Your logic flew out the window when you started getting emotional. 

Where did I get emotional? I didn't realize emotions were transferable through a keyboard. Please, teach me how to control them? 

Scarlet-Tech
Haha.   Glad you interpret that how you want.  Why not sell your EVGA stuff,  as you said you were,  and head out to better ventures in life?  Maybe you just like following me now?