Should a PC power supply work when removed from case and deliver 12V?

[stephenco]

I'm just removed the power supply from an old PC case which was working but when I connect it to a mains plug the fan doesn't even come on
I was wanting to use it to power an EIDE hard drive to format it

[RicheemxX]

Not without a few tricks How To / Turn ON PC Power Supply WithOut MotherBoard - YouTube

BTW why can't you just plug it into your existing PSU??

[stephenco]

Thanks for link to YouTube, I'll have a look at it now

I don't want to plug into existing PC in case I cause a spike so to prevent it, I'd have to power the system down to both attach it and detach it - I assume that is the case??

[RicheemxX]

Not really sure what kind of "spike" you'd be causing? Are you thinking the drive might pull too much power or something?

[stephenco]

Yes, disconnecting a circuit can (I've always believed) casue a surge

[RicheemxX]

You run no greater risk by powering the system down, which you'll have to do no matter what, and adding in the new HDD than doing what you are doing. You have to open the case, find an available IDE/PATA slot and attach the cable no matter the only additional step you are dropping is plugging in the power connector. You shouldn't be breaking an open, powered circuit that might surge anywhere

[JPMiller]

Before ANYONE gives anymore advice, we really need to know exactly what your doing and why...
Your post is confusing and incomplete, and from what little I could glean your going to cause more problems than your hoping to solve..

[stephenco]

If you follow the thread I've created in the technical forum for PC trys to boot, then blue screen, then 2 POST beeps, then reboots in endless cycle you'll see why I'm trying to power up a hard drive

[Taxmancometh]

All you have to do is get a paper clip and with the main board connector short the green wire with any black wire. This is what I have done.

Edit- Just watched the YouTube video and dude is doing the same thing.

[RicheemxX]

Yup its a pretty easy trick.

The OP got things all worked out though. This was related to his other thread amd instead of going through the setup mentioned here he just installed the drive back into the original PC and got things rolling.

[Taxmancometh]

Gotcha.

[stephenco]

Thanks RicheemxX for not just sorting the problem in the thread referred to, but for a great tip on getting the power supply working. It worked a treat!

[RicheemxX]

No problem, glad you got it all worked out