I have a very, very strange shutdown problem with win98.

The board is a tyan trinity 1854. I recently changed out the CPU cooler with a slightly bigger/quiteter one. For those of you familiar with the board, it has both slot1 and socket 370. I removed the plastic mounts/guides for the slot 1 to make room for the slightly larger cooler (don't think that is the problem).

But now, win98 does not shut down proeprly. When I shut down, it powers back the fans and the hard drive light starts flashing, but it does not shut off.

As strange as it may sound, I have traced this to the case fan. If I unplug the case fan, it shuts down properly. I have even tried a different case fan, same result.

I could probably get by without the case fan, or even hard-wire it to an unused drive cable, but why is it doing this? I am starting to think something on the motherboard is damaged 🙁