A few days ago my client called me and said they were having with their 2 year old Dell 2305 AIO computer. I went to the store and found after running the Dell diagnostics that the hard drive was failing. So I had Dell send out a new one to replace the defective one. I reinstalled the OS and ran the computer for two days, updating it before giving it back to my client. It was fine, I dropped it off yesterday, booted it up, no issues, and the customer was happy. Get a call from the customer this morning stating that they left the office last night around 6pm and left the computer running. Came in this morning and the screen is black and computer won't respond. Power light on side of computer is blinking Amber. Is it now a bad motherboard?