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Q: Fixed High Temps + Ghosting on 6800 Ultra Mac Edition AGP Graphics Card

Hello !

 

Hope its ok to post this " gave-it-a-go solution " on here ?

 

A while back my beloved 6800 Ultra Mac Edition AGP Graphics Card in G5 Dual PPC 2.0 behaved very strangely on start up ...


The desktop icon images had an immediate ghosting effect and the graphic card temps soared immediately to 62 Degrees C !

 

Did an instant emergency shut down ...

 

Replaced the Ultra card with an ati 9600 128 mb and considerd what to do about replacing this wonderful ultra card ? as the 9600 was really slowing down my graphics apps on my G5. The cost of a " new un-used vintage " Mac Edition 6800 Ultra replacement card was really shocking to say the least !!

 

So, I wondered if the fan on the vga cooler on the ultra card had died and/or the thermal paste had dried out and had caused the loss of contact between the graphics chip and heat sink ?

 

The old heatsink just lifted out so the thermal paste was completely dry !

Cleaned the graphics chip with some Polish 95 % Vodak and a coffee filter !

Used new thermal compound prior to mounting/ securing the new heatsink assembly

 

Well, I managed to repair the card for a total of UK £ 9 + shipping

 

Found a new compatible replacement vga cooler with copper heat sink

NQ-3851A - NorthQ 80mm Copper GFX COOLER

 

Had to modifiy the copper fins by bending them ever so slightly to avoid contact on the AGP slot/board.

Had to also modify the new vga cooler power cord as to to fit the original plug-in board fitting.

(Left the supplier fan-speed controller supplied with the new VGA cooler out of the wiring set-up).

 

Had to be very careful with the wiring (used v.thin cable wrap around the entire length to protect it) and due to the position of the heatsink, the wiring comes up off the card and is run along /secured underneath the top or ceiling part of the main compartment and then curves back down to the on-board card power socket.

 

Unscrewed all the outside (DVI to vga to monitor) cable fittings and retightened them, also had to move the vga cable to the monitor away from the UPS power supply cable - as the Ultra card seems to be more sensitive to electrical intereference than the 9600 card.

 

The new copper heatsink fan runs at full speed (approx 17 DB of noise) but the graphics chip is now a whopping 20 degrees C cooler under heavy load !

 

 

iMac, OS X Mountain Lion (10.8.5), APC Smart UPS 750

Posted on Feb 21, 2014 3:52 PM

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Q: Fixed High Temps + Ghosting on 6800 Ultra Mac Edition AGP Graphics Card

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