I fixed my A9800XT the way I was describing before and it seems to work
I simply plugged the fan cables directly to power supply. Below I give basic instructions for people who would like to fix A9800XT that way:
There are cables going from the card (there's socket close to the side where you're plugging monitor cable) to the fans. There are three: two for supplying power (red and black) and one for monitoring (blue). The idea is to deliver voltage to fans directly from power supply. To do that you need to cut red and black cables and connect them to directly to one of power supply cables (these that are connected to HDD, CD-ROM and also A9800XT itself). You simply connect red with red and black with black, of course they need to be made longer first. Remember to connect them from the side of fans, not the board
- we want to supply power to fans afterall. Special care must be taken to prevent making short circuit - you must be careful not to let any of black cables touch red cables. That's actually all that needs to be done.
Theoretically blue cable can be left plugged to the card so that fan speed can be still monitored. I didn't leave it in, I'm not sure if it's safe, so try it only at your own risk.
If I had digital camera I would make some pictures to make it easier for others.
I don't guarantee this method works 100%. I've just done it that way with my card and it seems to work, but some burn-tests still have to be made.
I wish every owner of A9800XT that they don't need to fix their cards, but if they do I hope this post will be of some help.