Technically, a motherboard failure (Described as a NO-POST) is when the system will not turn on, & make a display. There a varying degrees of a motherboad failure too. You can have a failure of the whole board (nothing works) a bad slot for a PCI card or RAM memory module, failure of the floppy or hard drive controller, or failure of other integrated devices like a Network card or sound card.
A hard drive failure (describes as a no-Boot) is when the primary storage device, (where programs & the operating system are stored, along with your data) has failed. This like the motherboard, can be partial or complete. A total hard drive failure will display an error like "no bootable device detected" "NTLDR error" and the favorite "press F1 to continue, F2 to enter setup". A partial hard drive failure may include inability to read parts of the hard drive, corruption of data, or inability to load the operating system at boot, but still be able to read data.
Hard drives also now have SMART (Self-Monitoring Analysis and Report Technology ) that may be able to warn you of an impending hard drive failure in time to back up you data, before you have to replace the drive.
A SMART error looks like this:
WARNING: Dell's disk monitoring system has detected that drive 0 on the primary EIDE controller is operating outside of normal specifications. It is advisable to immediately back up your data and replace your hard disk drive by calling your support desk or Dell Computer Corporation.
Hope this helps
Inspiron E1505 Windows 10 / XPS 10 Windows RT
Dimension 8400 Windows 7/8
Thank you for your quick and very thorough response.
My computer was giving me intermittent problems yesterday, with reboots, error messages and the likes. Some error messages happened only once and a different message would appear the next time. I did a disk cleanup and defrag - still had some minor problems. Today I opened the box and vaccumed it! No problems on startup!
Same thing here, Judy. Ran all the checks I could find over three days, no idea if my drive had failed or the motherboard had given up and a search brought me here. I vacuumed. Afterwards, it was up and running fault-free for nearly eight hours until shutdown yesterday and today, a clean startup. I daren't quite declare a winner but for my money the girl solution has the rest beat!