I have an Asus P55T2P4 motherboard Rev 2.1. It has a Pentium 133 and 16 MB (2x8MB) of RAM. The RAM sticks are not matched, but test up OK on post. There is a 1.44MB 3.5" floppy drive connected to the on-board floppy controller.

The problem is that no matter what I connect to either the Primary or Secondary IDE connectors, the system simply does not detect anything. I have tried every conceivable device, cable, and BIOS setting, but have had no success. Hard drives, CF adapters, and CDROMs are simply not found. Settings - both "Auto" and explicit - make no difference. The system attempts to detect a device on Primary, Master - does not detect anything - and then boots DOS from the floppy.

The only thing about the system that is unusual is that I de-soldered the Benchmarq NVRAM/RTC from the system and replaced it with a socket. Then I did a battery hack on the component and put it back in the socket. This seems to be working well as the system no longer complains of battery failure and the BIOS configuration saves OK. I looked at the board where I did the work and it seems just fine. I cannot remember if I ever saw the system detecting a hard disk before the clock chip replacement, but something is bugging me that I did.

Any troubleshooting advice would be deeply appreciated.