new PSU - sometimes won't turn on, keyboard/mouse lights flashing

[aardvark]

i just got a new PSU as the last one broke - installed it outside the case started fine.
put it in the case, wouldn't start and the keyboard and mouse lights were flashing.
checked all the connections, wouldn't work. Took it out, unplugged everything, plugged back in - works.
put psu back in case - doesn't work.

tried disconnecting everything and it might be the keyboard (its PS2) - unplugged and plugged back in and the lights stopped flashing and the pc turns on.

thats where i am now and i'm using the PC now (obviously).

my question is: can a faulty keyboard do this?

it should be noted that i am passing the keyboard through a hotrod joystick (ps2 to joystick, another ps2 lead to the pc).
as i said it seems fine at the moment but it may happen again and i'm wondering if anybody has heard of such a problem??

 

[Kennysevenfold]

Have you another kboard to hand?

 

[aardvark]

i haven't, no.

i could probably find one at work - thats a plan.

i just found it odd and wondered if it was possible for a keyboard to do this - i hope it is, rather than it being something more serious.