With this problem, I eventually decided it was a failing power supply…but now I’m not so sure…

The PC was brand new (meant to be a gaming PC), but when 240V was connected, the power LED would blink, and the PC wouldn’t start. So the seller (a Melb. company) gets me to go their customer and fix it on their behalf (to avoid shipping costs).

After a process of elimination I zeroed in on the power supply.

I removed the 20-pin MOBO connector, shorted the “go to full power” pins (on the 20-pin connector), and the power supply came to life… Hmmm, maybe it isn’t the PSU after all…

This is the 3rd time I’ve seen 20-pin power supplies connected to a 24-pin motherboard. I always feel uncomfortable when I see this.

OK, I plug in the PSU connector to the MOBO again, and the PC started up (for the first time since the customer had taken delivery). I checked out the screen resolution, and after 5 minutes, I declared that the there must have been a bad connection with the 20 pin connector.

I shut down the PC, put the side panel back (it has an exhaust fan, so I plug it in as well), then fire up the PC, but I just get a blinking power led (again)…

I take a guess that the exhaust fan might be causing a problem, but after I unplug it, the PC still won’t start.

OK, it must be a faulty (brand new) power supply… Its probably just on the verge of failing.

I go get another PSU from the car (it has a 24-pin motherboard connector). And by using this PSU, the PC starts first-time, every time.

Good, I swap PSUs, help out with a minor display problem, and I’m on my way again.

Later, I do some research on 24 pin and 20 pin PSUs and MOBOs, and I discover something new (and interesting):

You can plug a 20 pin PSU into a 24 pin MOBO… but it might or might not work. It seems that the extra 4 pins are for some of the more demanding motherboards, and for PCI-e video cards…

Hmm, the customer had a video card (but I’m not sure if it was PCI-e).

So, its possible that the PCI-e card wasn’t getting enough power, and was preventing the whole PC from starting.

I also get to keep what I now realise is a perfectly working, new PSU… Just as well, as the Melb. seller complained about how much I’m charging (they say it should have been a 10 minute job…), and complained about what I charge for my PSU… If I don’t agree to their lower fee, its implied that they won’t pay… So I lose out on $35, but I gain a $75 PSU 🙂

i’d say megapc need to be more careful about how they build pcs.