There almost always is.
This jumper is to discharge CMOS with the battery in - but it's still advised to unplug the power supply cables to the motherboard. Without the jumper (or unable to find it) you have to remove the battery and disconnect the power supply cables (even with the wall cord unplugged, a powersupply may have enough residual voltage to keep CMOS alive for as much as half an hour).
Discharging the CMOS will sometimes return an insane computer to normal. Apparently there's important stuff in there the CMOS setup program doesn't touch.
