Firewire on Macbook pro - not enough power...

[daz777]

Hi guys,

So I connected my digital back (sinar54h) by firewire to laptop (old macbook pro 17) and it works fine. But as soon as I use any of the additional interfaces, for example Flash Sync Interface, connected to digital back, that interface does not work, although digital back continues to work.
That happens only on battery - when laptop is powered from mains, everything is fine.

So I thought that probably firewire port is slightly under-powered, and to test it, I just bought friewire repeater with external power adapter.
Unfortunately it still does not work.

Im not sure, if my repeater is powered with too little of a current (it is powered with 9V, 1.5A adapter), or should I look for better battery?

Can you guys please tell me, are there any portable options that work, powered from batteries, that actually provide enough current for firewire port to work?
Would it help if I buy external power bank type of battery for macbook?
Or should I rather look for stronger repeaters/hubs? If so, what makes and models are reliable and work fine?

Thanks!

[mediumcool]

Do you have a dealer who you can talk to? Perhaps you could do some tests with them; what else is a dealer good for?

[BobShaw]

It certainly sounds like a power problem. Can you get the specs for the back?
Firewire output power is 7W. Long cables would reduce that.
If it works on mains power for the laptop then the easiest solution is probably a battery powered inverter for the laptop. OK if the car is beside you.