also hope everybody had a good christmas and a happy new year

Just reread the OP. Are you saying the unit is not getting power from the FW cable?

Is this unit new or been used a long time? Have you been religious about plugging/unplugging the unit with both the PC and unit off?

The "no light" on the unit may mean the internal power supply (or fuse) is blown.

hi met, its only the fw light which is off the power and lkd light are on. I've tried it with just the firewire powering it and the power supply just cant get that fw connection going. the unit itself was brand new last christmas not used it much at all. cant say i've always had both things off when plugging and unplugging i know theres warning messeges about it but i'd hate to think that doing that a couple times had killed it :/

I don't have this interface but did a quick search and found this:
http://forum.cakewalk.com/POSSIBLE-SOLUTION-to-Focusrite-Pro-40-Win-10-update-and-VIA-1394-chipset-m3346353.aspx
 
At least one person has solved this on Windows 10...

On Win7 mine runs using Windows legacy drivers on a VIA chip, so it is a pretty tolerant unit. Does MixControl show "no hardware detected"?

You may want to contact Focusrite again on this, since getting power but not connecting is incredibly odd. Also ask them a " what if" scenario about connecting it powered and what is most likely to be damaged.

Anyone running Win7/8 (or Mac) with a FW port would just need MixControl installed to check on their machine, but be sure to have them both off when connecting the cable.

Win10 had known VIA issues, so I would avoid that possibility on another computer.

@pat thanks for the link unfortunately just tried it and it didn't work. @met yeah it says no hardware detected I've emailed focurite asking if i can send the unit to them to have them check it over but i will try it on someone elses computer with mix control as soon as i can i'll have to hook somebody up with a free firewire port got so many cards going spare now lol :(

So i've sent the unit off and i got an email today to say it is definitely broken but they're not even sure whats wrong with it so they are going to send me a replacement one which is awesome as the unit is out of warrantee. So should have no more problems when the new one turns up. Id like to thank everybody that helped me out with this issue if it hadn't been for you guys getting me to try everything i never would have sent it off in the first place. Many thanks! :)

Awesome news on the replacement! Please be sure the unit and computer are both off before connecting the FW cable on the new one.

I will do I've learnt my lesson with that lol