About every 1/5 boots, my system, a Lenovo PC running Linux Mint 17.2 as the sole OS, will fail to boot. When this occurs, I have to power down and power up several times to get it to boot again. Reinstalling Linux Mint did not help solve the problem. I have run SMART tests, the Lenovo Diagnostic USB, and badblocks and no issues were found. What could be the problem?
Could be a bad motherboard. Check the capacitors. If the tops are domed up then they are bad. Sometimes they leak at the bottom where the leads are. Maybe it is a heat issue. Check the fan blades and clean them if needed. Also check the heat sinks. They must be clean to cool properly.