PC won't boot - it trys, all fans run for approx 5 secs then shut down and start again!

[St Ivo]

Hi all,

I have just joined in the hope that someone can point me in the right direction. My self build (mainly video editing) PC has been running fine since I re-built it six months ago. This evening I tried to wake it without success and had to press the case reset button. It then started to boot, fans running at least, but then stopped after about 5 secs before it restarted and went into a never ending loop of starting and stopping. I have not changed anything hardware, software or BIOS that might have caused this.

I don't have any spare components to substitute for diagnosis so I hope someone can give me a clue as to where to start please.

MB: GB Z97-HD3 Rev 1.0
BIOS:F6 06/11/2014
CPU: Intel i7-4790
GPU: On board
PSU: Antec 550w True Power Classic
Mem: 2x8Gb Kingston DDR3-1600
OS: Windows 10 Pro.

Any help would be much appreciated. TIA.

[LouBraun]

Re: PC won't boot - it trys, all fans run for approx 5 secs then shut down and start again!

Try disconnecting all external devices except for your keyboard and mouse and see if the system boots. If the on-off fan issue still remains, recommend removing all memory sticks except for one and try again. This problem can easily occur if there is one bad stick.

[boe323]

Re: PC won't boot - it trys, all fans run for approx 5 secs then shut down and start again!

A very similar thing happened to me, id just finished flashing a succesful bios flash, rebooted into bios , checked it and then rebooted and updated the backup bios with success, the pc powered off after backup was flashed. I went to turn on the pc and it started boot looping ...switching between backup and main bios on every restart, I thought I borked it. I crossed the bios chips to try recovery, took it to a shop and got lied to saying they changed the bios chips and changed this diode and that etc but they couldnt solve the problem, they couldn't solve it cause they didn't do anything. After a month of being lied to, I went and fetched it back to use the parts for a new build(after saving up). I thought to myself, ill plug it in anyway and have another fiddle, and the bloody thing started lol, I traced it to the the 2 top power leeds which I think is separate power for the ram, seems the socket has become a little dodgy and if you knock the socket or the leeds it cause the bootloop, so maybe you have a similar problem to me, try the power leeds at the top of the board and the ram sockets.