Desktop, no power, causes?

[Mayhem]

Aside from the power supply inside going funny... although everything was working fine apparently upon being switched off the previous night, the PC fails to start anything when the power button is now depressed. Just sits there like a big paperweight.

Just assessing possibilities... it might be the last kick my parents need to get a new machine finally though...

[kernow]

It does sound like the power supply to be honest.

[abigsmurf]

do any lights come on at all? either at the front or the back? Checked to make sure none of the power connectors on the motherboard have come loose?

If the connectors are fine and no lights or activity at all when you press the power button, that leaves 4 possibilities:

PSU has gone.
The motherboard is fried.
The power button has failed
the fuse in the plug itself has blown.

[speedlolita]

Reset CMOS, discharge motherboard and stuff too.

To rule out the switch being broken, bridge the pins required to start the PC.

[Mayhem]

I did check the fuse in the plug, or if there was an issue with the power strip, but both were fine. I had considered the power button itself, not sure how I'd bridge that given it's a Dell machine and the cases are fairly proprietary. No lights, no nothing when the button is pressed, and yes I did open her up and check the connectors etc. In the meantime my mother will be getting one of my brother's old laptops to get online...

[Kaido]

If the fan in the power supply is dead and there's no beeping then its likely a dead power supply.

As smurf said there are other possibilities you could eliminate.
To rule out the power switch you could hook up the power to the reset switch and press and hold that for a moment.

[Mayhem]

No reset switch on the case, it's just the power button. As I said, Dell cases tend to be fairly proprietary and incongruous with how I believe cases should be...

[Mayhem]

Parents are talking about possibly getting a laptop as a replacement, as that would also allow them to take it while travelling. All well and good, but they still would need to get the data off the old desktop drives first. So, best places to get exterior USB caddies to mount them? Don't have any other desktops left around I'd be able to transfer from you see...

[abigsmurf]

Ebuyer probably do them for dirt cheap.

Not sure you can get enough power from USB for a 7200RPM drive so you may need to get a powered one.

[Mayhem]

Yeah, I was thinking that myself... I just meant "USB" as a method of transfer here, not necessarily how it would be powered. 2.5" is laptop size, and 3.5" is desktop size, right? Just so I don't screw up the caddy I buy hah hah... I at least already known I'd need an IDE one...

[sj33]

3.5" is what you want. 2.5" drives can be powered over USB, but 3.5" will use an external power adaptor.