This article will describe how I installed a Tennmax Lasagna (from my old Diamond Viper 550) on my Viper 770 Ultra. If you've never done this before, removing the heatsink from your favorite graphics card can be an unnerving experience. After all, one slip with that screw driver, and you just ruined a 200 dollar graphics card...
If you attempt to copy what I am about to describe here, you could damage your graphics card and invalidate the warrantee. One slip of your hand and whoops! Here's a simulated picture of what could happen. Ugly, huh? :)
Removing The Fan
The fan on the Viper 770 is held in place with 4 screws. These can be easily removed (shown below). I had a problem with the two wires that carry power to the fan, which are attached to the board by a small piece of glue. I was hoping it was a rubber based glue that could just be pulled off, but it is very hard. After picking at it for a while, I gave up and cut the wire on either side of the glue and left it there.
Removing The Heatsink
The heatsink is attached to the chip with thermal conductive glue. This glue is easiest to work with when the chip is cold and the glue is brittle. To remove the chip, I wedged the tip of a screwdriver between the corner of the chip and the heatsink. Twisting the screw driver with a gentle pressure is normally sufficient as the heatsink will literally "pop" off. Before doing this, I probably should have stuck a couple of layers of masking tape on the card around the chip.
After removing the heatsink, the sight before you can be pretty ugly. Some of the glue will remain stuck to the chip and it all must be removed.
At this point, I put masking tape around the edges of the chip to offer some protection. This is where it's real easy to slip and cut a big gash into the card. Large clumps of glue can be chipped away with the edge of a strong sharp flat knife.
When handling the knife, the edge of the knife should be kept flat against the surface of the chip. If
the knife is held at an angle, the tip of the knife can cut scratches into the chip. You'll want to remove the glue, but keep the surface of the chip as smooth as possible.
The smaller pieces of glue can be shaved off with a razor blade. Be careful not to cut yourself! Once all the visible pieces of glue were removed, I sanded the surface of the chip with very fine sandpaper. The final step was cleaning the chip with carburetor cleaner and rubbing alchohol.
Tape And Attachment
To attach the Lasagna to the chip I used some heat conductive tape. This tape can be ordered online from Tennmax. You can also get similar stuff from HardOCP, which is probably better :). This double tape is easy to use and already cut into little squares. Just stick one side labeled "metal" on the heatsink, peel off the other side, and stick the heatsink on the chip.
This tape isn't tacky like normal tape is. If the surface of the chip isn't perfectly flat and clean, then it will drop off. I then took the heatsink back off and inspected the underside of the tape. The tape will change in reflectivity where it has made a good contact with the chip and remain the same where is hasn't. If it looks good, then I clean the chip and heatsink again and apply a fresh piece of tape.
So why did I do all this? Well, first of all I wasn't confident that the OEM fan was performing as it should since it was making a lot more noise than is usual for a healthy fan. Second, I wanted to see if a bigger fan would provide sufficient extra cooling to get my core speed stably overclocked to 175MHz (it's 170 at the moment). It didn't really help as my system still crashed at 175MHz after a few minutes of game play.