I started out with a flashing battery icon. Ran diagnostics to see what it could mean. No problems were found. I contacted Dell. They sent out a tech who said I needed a new battery. Replaced the battery. New problem appeared. System was getting stuck in between sleep and hibernate. Dell sent another tech who replaced the motherboard and the heat sink. Did not solve problem. I changed power settings so system would never sleep if it is plugged in. Now I find that I cannot restart. System just shuts down, I have to start it again by pressing the power button. Dell tech walked me through deleting two partitions and re installing the OS from the recovery disk. Still can't restart in the normal manner. Thankfully I have an extended hardware warranty. Dell tech support is "researching the problem."