Understanding Meaning of Power Indicator Blinks for Gigabyte GA-B85-HD3 Motherboard

Question

I've bought a new desktop computer few days ago. It has the following hardware specification:

• Gigabyte GA-B85-HD3 motherboard
• Intel Core i-5 4460 Processor
• 8 GB DDR3 RAM
• 1 TB Hard disk
• Windows 10 Pro x64 Operating System
• Value Top 450W Power Supply
• ASUS VX229H Monitor

The machine is acting strangely from today. While my wife was using (nothing fancy, browsing internet) it, it suddenly got restarted. The computer was stayed in shut down state (nothing on the monitor) but the power indicator on the front panel of the casing kept blinking. It's blinking pattern is 3 seconds on, 5 seconds off.

After several trial and error, and checked and reconnected all possible plugs, I was able to start the machine and my wife was able to log into Windows. But after 5-10 minutes again the system got restarted and stayed in shut down state with blinking power indicator (3 seconds on, 5 seconds off).

What could possibly is the problem? Every component on it has warranty but before taking the machine to the vendor, I'd like to understand the problem and if possible, apply solutions.

Answer 1

For random shutdowns there are two things I would strongly suspect: the power supply, or overheating.

I can't find any information on the Value Top 450W, but based on images I'd suggest it's a very old style -- most likely terrible quality -- PSU that shouldn't be used in a nice new machine.

If you have access to a spare power supply, I'd suggest trying that. Regardless I'd consider buying a new decent quality power supply, as I don't think I'd trust the Value Top one myself.

To check if your CPU is overheating, download a tool like HwMon and see what it says. Temps should be around 30-40 degrees at idle, and no more than 60-70 under load.

The other candidates I can think of are:

• Motherboard. You can try resetting the CMOS by shutting down, unplugging the power supply, and then removing the battery on the motherboard for 5 minutes. This fixes strange problems sometimes. Identifying the motherboard as the problem part is tricky though, normally it's a process of elimination of all other parts.
• Hard drive. A faulty hard drive can sometimes cause strange system stability issues. I'd suggest this is an unlikely cause in this case though.

So, it's very difficult to tell without actually testing, but I highly suspect power supply if CPU temperature is okay.

Edit: As to an answer for your actual question, I don't know what the blinks mean. For whatever reason, motherboard manufacturers don't seem to include their own beep codes any more in manuals, let alone flashing patterns on the front-of-case LEDs. But hopefully someone knows and can tell you exactly.