I've built a HTPC and it's been running happily for about a week whilst I am getting it configured. Tonight however I pressed startup, went for a cuppa whilst it booted and came back to find just the HD light on but the power light off and the 'puter doing nothing. Pressed reset button and this time, nothing, no lights no activity, no fans, nothing. Despairing I checked all fuses and such and tried again to no avail. Opened it up - there is a power LED on the ASUS mobo and that is lit - indicating power to the mobo from the new 300W SilenX. Checked all cards and connections were seated ok but still no activity when trying to boot. Hauled my work computer in and pulled it apart - swapped components between the two and after an hour of fiddling I found that the noisy but trusty old 250W PSU in my work computer will startup the HTPC but the new 300W SilenX won't. Can anyone more technical than I explain what could have happened - especially since the (broken?) SilenX makes the power LED light up on the mobo but it won't startup with the SilenX attached. Shouldn't the SilenX either be dead ( in which case the mobo LED should be unlit ) or fully working ? I want to be fully armed with some possible fault reasons when I phone up the supplier on Monday to ask for a refund. Thanks in advance.