Has anything happened prior to laptop failure? The error may be due to a motherboard failure, but nonetheless you must try to make a reset of the BIOS. It is made by replacing the CMOS battery.
Have you tried replacing this battery already? If not, you have to do that only after you have pulled out the battery and the power cord of the laptop. Open the lid and localize the CMOS battery which lies next to the processor and it looks like a watch battery. If you have another CMOS battery, you can replace it with that. If you don't, leave your current battery aside and wait for some minutes for the electricity to discharge. Then, plug the CMOS battery back in and the power cord. Try to boot your laptop again.