Question New Build won't turn on - Power Supply works with other MOBOS

[Daniele_2]

Hi all,

(Quite new to the PC building scene)
I had just finished building my new build and was waiting for my rgb fans to arrive. I switched on the system without a monitor or anything just to see that it all powered up and it did. 2 days later the fans have arrived, I switched the system on again just to check and it lit up and switched off abruptly (not like it did last time). Now it won't switch on at all as if it is not plugged in.

I have tested the PSU by jumping the Ground(green) and the black wire on the ATX cable and connected it and the fan started and worked well. Any suggestions on what it might be/tests I can run. I also connected it to an old motherboard and the motherboard's light indicator switched on. Unfortunately the new motherboard doesn't have any lights. PSU fan did not move

Do not hesitate to suggest something that I might have been stupid enough to do as I am quite new to this.

 

[rgd1101]

full system spec? include make and model of the psu

if it work before the fans. unplug those fans?

 

[Daniele_2]

I switched it on again before I plugged the fans (and it didn't turn on)

System Specs:
Intel i5-9600KF
Gigabyte B365M D3SH
Corsair Vengance LPX 16GB (2 * 8GB)
Palit Geforce GTX 1050ti
Thermaltake Smart RGB 700W 80+

Case: CoolerMaster Masterbox K500

 

[Daniele_2]

Update: I have also tried jumping the motherboard to test the power button and removing almost all other components. The old motherboard turned on with only the Main Power Connector and the ATX 12v 4+4. I have also connected an old graphics card to test whether it would run it and it did.