Like any gaming machine, if you replace the batteries, a clear is necessary in order to redo the nvram to a working state. Backed memory appears to be NVRAM, Thre is no cracked card of any type, it is probably just the way they tell you that the nvram did not pass the test, as it probably shouldn't since you replaced the batteries. The batteries on all gaming machines are used to maintain the configuration and play history of the machine, when you remove the batteries to replace them, all of that disappears. That is why you need to clear machines, like you do with the bally alphas after any kind of battery change. The work-around is to replace the batteries while the machine is powered up, so that energy is never removed from the nvram, but you have to be verfy careful when you do this as the machine is energized and any kind of short can cause severe damage.