T400 beeps when typing non-alphanumeric characters

[hedron]

I have a password set for both to enter the BIOS and regular boot. It was working fine the last time I used it. I didn't do anything but leave it in a corner for a few weeks. The password screen will come on, I type my password, but when I type the carot character ('^') the thinkpad beeps at me and no character is typed. It will beep when I type any non-alphanumeric character, whether it's the period or the pipe.

I have tried removing the battery. Also, I opened it up and disconnected what I believe to be the BIOS battery. It's wrapped in yellow rubber balloon and underneath the trackpad next to the main hard drive bay. I reconnected it, and booted it back up, but it's still the same, only it complains about the date and time. I don't really care about that, I just want to be able to input my password.

[RealBlackStuff]

If it complains about Date/Time, it's because they were wiped when you removed the yellow CMOS-battery.
It will stay that way until you manage to get into BIOS again and set them.
AFAIK older TPs do not use non-alphanumeric characters, are you sure you use the correct password?
Anyway, here's a tested method to remove that SVP.
The EEPROM can be found here