I have a Fireface400 which  isout of warranty - I've always used the original KTEC PSU, but the other day, my Fireface's hexadecimal LED window started flashing...all the red  'clip' LEDS came on dimly (and flickered).

It transpired at if I flick the switch to firewire sourced (vs the external PSU), the fireface works....but my ground from my PC is noisy, so I'd rather have it powered off the external  PSU. Tthe PSU measure 12V fine on my DVM (albeit I can only measure it 'un-loaded'...ie not when it's connected in to the PSU).

I'm just wondering here if there's any known issue - becuase at the minute I can't be sure if it's the PSU of some related PSU problem inside the fireface 400 unit.