Sounds like a faulty psu to me jock.
Check the wattage,you should be looking for something in the region of 500w upwards really.
The only way to check this,is to look on the psu itself,you may have to remove the psu.
Also how much ram is installed ?
Galaxy Note 8 vs iPhone X
Graphic tees: 14 best websites to find your next T-shirt
How to update iOS on iPhone or iPad
Les meilleures applications pour enfants 2017