Making an NV-68 Bracket to fit 7800GTX Card

[coolmiester]

I couldn't wait any longer for the new Danger Den NV-78 blocks to arrive so took it upon myself to have a go at modding an NV-68 block and just thought i would share my new creation with everyone.

The main problem was the Lucite back plate on the NV-68 which covered some of the memory chips on the new 7800 cards and i've seen a few people hacking the Lucite to fit always looks a bit getto for my liking so decided to make one from scratch.

Got myself a bit of 6mm aluminium and using the original Lucite top marked out the four holes to get a reference then basically measured where the chips were and laid it all out on paper so i could sketch the basic shape.

Tried to keep all the lines nice and flowing so it looked nice......obviously

Once i was happy with the shape i cut it out so i had a template to lay on top of the card lining it up with the holes to make sure it all fitted nice, then stuck the template onto the aluminium.



Then out with trusty fret saw and cut round the paper template


and ended up with this nice little object which when placed underneath the original Lucite plate you can see its basically the same but with the curves much more exaggerated.




Quick bit of lapping to the top and sides


and then onto the polishing wheel


Then clamped the Lucite top to it to get the holes lined up and exactly and went ahead and drilled the 4 holes followed by cutting the neoprene to size




The next bit has been seen a few times before but i may as well run through it incase anyone wants to see how its done.

On the 7800 cards there are also a few resistors that protrude higher than the actual memory preventing the block to come in contact with the bits its supposed to.

I've circled in red the ones on this particular card which is a Gainward 7800Ultra GTX Golden Sample but there may be variations between different cards so it may be worth checking.


Basically what you need to do is identify the protruding resistors and put a small dab of Arctic Ceramique on each one then lay the block on its back and then carefully offer the card down into position. Take the card away and you will be left with a little blob of Arctic Ceramique on the block form the offending resistors..


You will find you only need to dig out about 1mm of copper using a Dremmel with the small grinding bit so it looks something like this...


Obviously brush away all the copper filings and offer the card to the block once more just to make sure you don't get any Arctic Ceramique which providing you ground out the correct area to the correct depth will indicate that the resistors no longer interfere and the card will lay flush onto the block.
You can then follow the NV-68 Mounting Instructions

Anyway, i'll leave you of a few pictures of the finished bracket which show the memory chips can now take ram sinks which in this case are shiny Tweakmonster ones.

I've now got to make another one for the other card and get them put back into the Shinymaster

[coolmiester]

And then there were two




Well i'm not to sure if anyone else has had a go at cooling Sli 7800's with NV-68 blocks so here you go :smile:

Took a bit longer than i would have liked but the polished aluminium brackets fit in good with the shiny case and at last its all back together and being leak tested so should get a comparison temp wise over the stock air cooled later.

Fingers X'd

[flatline]

id have been tempted to make the alu suport cool 3 of the 4 ram chips but more time needed to do that

grats very cleen i like it alot

[killernoodle]

Damn, dually 7800GTXs?? And I'm still watercooling an antique 9800pro

[allnighter]

Very nice. I have the same prob an am very tempted to try it. I wish I had all the tools at my disposal to achieve such a nice finish. Never the less, I might give it a go and see how it works out. If it doesn't turn out ok I can always pick up a new 78 block . should be out any day now.