VERY unusual POST issue Thinkpad T43

BACKGROUND
My brother gave me his lappy and simply said "it won't turn on". After I investigated, I realised what he meant was that it froze on the POST screen. Trying to enter the BIOS didn't work; the computer was literally frozen on the POST screen.

STEPS TAKEN SO FAR
I removed every imaginable component one at a time, including the monitor, NIC, RAM, keyboard, and even the modem, all to no avail. I removed the CMOS battery for a long time and it didn't do anything either.

CURRENT STATE (where it gets interesting)
I put the computer back together and decided to just let it sit on the POST screen. I pressed the "access IBM" ket just for kicks. After about 5 minutes of sitting there the maachine went into the BIOS setup?! I tried navagating through the menus and noticed that the cursor would move, but it lagged....really really bad. The lag time varied between 1 and about 45 seconds. I have been able to consistently duplicate this behavior. I have not tried booting into an OS yet (the HDD is still removed from the machine). The ONLY thing I can possibly think of is bad RAM (I mentioned that I removed it, but it only has one stick and I don't have any extra PC 2400 or whatever it takes laying around to swap it out) or bad mobo. ANYBOY KNOW WHATS UP?!?

Thanks

I've had 3 IBM T40-41s, all with system board failures. If I had to guess, I would say your north bridge is jacked and the only way I know of fixing it is to buy a new laptop.

I've had one T40 that one day just decided to stop powering up, one T41 that would POST and then lock much like yours, and another T41 that would run for 30 seconds (in BIOS or not) and then turn off. I troubleshot all the problems to the north bridge as the north bridge on all three of them got really hot. You could try ebay for a new system board but its probably less trouble just to buy a new comp since T40's are only $150.