Originally Posted by redtree
Is the white 4pin power cable properly seated to both the PSU and mainboard?
The problem could be related to the PSU's 5.5V line. A multimeter would be helpful I guess, but if you have another 2K Slim you can see if the PSU powers the standby led.
If it's a mainboard fault we need
on the case
All cables and plugs are nice and tight, I've tried a psu from a 2503b same problem. Might nip out and borrow a multimeter as I know
is gonna insist on me having one to hand.