Computer failure

How to turn on an ATX power supply (connect pin 4+5)
How to turn on an ATX power supply (connect pin 13+14)

Last weekend the PC I use as mediacenter (xbmc/vlc) wouldn’t boot anymore. It would turn on, but then nothing would happen, just a black screen, no BIOS messages, no beep, no nothing.

Trying to debug the system I unplugged all non-essential hardware (disks, pci-cards, usb, video, etc) and re-seated the memory. The system still didn’t respond, so I carefully inspected the mainboard for busted capacitors or other possible failures, but I couldn’t find any obvious issues.

When I turned on the system the powersupply fan and cpu-fan would start turning, but nothing more. I expected the mainboard to be dead, or maybe the bios to be broken, both things I couldn’t really fix myself, so the system was a write-off and I was looking for a replacement.

I ordered a new Dell Studio system, as that seems to be a good replacement for mediacenter use. It’s small, looks nice and has enough power to play back HD media. Another nice feature of this system is that it had a HDMI interface to connect it to my HDTV.

I was still fiddling with the pc when I friend called and suggested that the power-supply might be faulty. I still had a brand new power-supply lying around which I got at eth-0, so I swapped it with the old and noisy powersupply and booted the system.

The fans started spinning and *BEEP*, there was the all to familiar on-boot beep telling me that the system seemed to be working again. I turned off the system again, reconnected the harddisks, plugged in the videocard and closed the case. I connected the system to the tv and could finally watch some movies and series again 🙂

While watching the remaining Firefly episodes I decided to test the old/failed powersupply, and looking on the web for the correct pin-out/voltages and the method to turn it on (connect pin 13+14 with a paperclip). My multimeter told me that all pins and voltages were correct and within specifications, so it seems that they might only be wrong when put under load. I have no idea how to test that, but i’m open to suggestions… otherwise I’ll just bin it, as it was a cheap supply anyway… but I should get a new spare… you never know when you need one.

I expect the Dell Studio to arrive in about 2 weeks… but I’m happy to have fixed my older system again, as it’s the only system I have which has halfway decent (nvidia 6600) graphics hardware (all other systems use in-chipset video (intel 945, sis, via) for playing games.

A review of the Studio will follow asap.