Picture would help. Assuming this is a Reel Touch machine the battery in the top box probably needs to be replaced.
Open the top box and replace the coin battery.
Now you will need an old computer ps2(small purple plug) type keyboard plug it into the side of the top box.
Turn on the machine and keep pressing the delete key on the keyboard until the bios screen appears on the top box.
Set the time and date and then save "Optimized Defaults "
After saving turn off, unplug keyboard and you should be back in operation.
Rich