Hi chiefJustice,

It is true that the Ati Mobility Radeon 9600 runs too hot to be used un-modded in an Inspiron 8500. However, this is not the case for an Inspiron 8600, the bios of the 8600 is set to a higher maximum heat threshold. This coupled with the lower operating core temperatures of the Pentium M should allow the 9600 to work without any problems on an Inspiron 8600.

Nevertheless, in your situation your video card may be overheating, do the lines show up the moment you start up your computer? A good troubleshooting idea would be to plug in an external monitor and see if the lines still show up. If they don't, then the problem would most likely not lie with your video card. However, if the lines still show up the moment you start your computer then your video card is probably defective/damaged in some way. If the lines only show up after extended amounts of use or gaming then a viable solution would be the use of an external laptop cooler. I currently use the Vantec Lapcool2, without it I would not be able to run certain games without a noticeable drop in frame rates. Another thing you could check for is the presence of dust congesting your system heat syncs and fans.

If you would like to know what the operating temperatures of your system are then you can download and use any temperature measuring utility. I currently use fangui, which you can get here: http://www.diefer.de/i8kfan/index.html . This utility allows you to monitor your cpu and gpu temperatures along with the temperatures of other pieces of system hardware. If also allows you to control the speed on your system fans, you could try setting your fans to always run at high speed to see if that is enough to alleviate the heat issue.

Another option would be to modify the heat spreader on your video card; this would involve removing the thermal pad and replacing it with a copper shim. You can get more information on this from the url you posted in your message. This solution would greatly improve the heat dissipation from your video card. However, I do no recommend this since it would void your dell service warranty. Unless your warranty has already expired or you know that your video card is not defective/damaged in some way you should not consider this as an option. Hope this helps :smileyhappy: