system won't boot after adding a harddisk

[jeditech1978]

Hi together,

maybe somebody here have had the same problem and can give some hints.

Yesterday I added a HD to my self-built system. The HD was used in an external case. After that the system wont boot any more. No leds, fans dont turn, absolutely nothing. First I thought it was the PSU. I have another one at home but the switching the PSU didn't help. Now I think there are only two possibilities: either the Mobo or the case (power switch). Mobo is MSI X470 Gaming Plus, case is Sharkoon BW-9000V, both are only weeks old.

Some system information:

Mobo: MSI X470 Gaming Plus
CPU: Ryzen 71700
RAM: 2x 8GB Ballistix Sport LT 2400
Graphics: Gigabyte NVidia 1070
PSU: Corsair RM850

Everything worked fine just before adding the HD.

Grateful for any idea.

 

[Tolis_GR]

To test the mobo, simply pull out the power switch connector cable of the case, and touch the 2 pins with a screwdriver.

 

[jeditech1978]

@Tolis_GR thanks for the reply. I replaced the power switch with a jumper and turned on the PSU. Nothing. A fan which is directly connected to the PSU started turning for one or two seconds and then stopped. No leds blinked.

What now? Can the CPU be the reason (though I didn't touch it at all, nor the CPU fan)? The PSU can be excluded as the cause, tried two different ones, both worked fine in another system.

 

[jeditech1978]

Just put the CPU in another system and it worked fine. It has to be the mobo.

 

[Tolis_GR]

Most probably it's the motherboard. If it doesn't power up with the jumper, then it should be dead