Will sticking a 12V DC power adapter on a 5V hub fry it?

[Eug]

I have a Firewire hub which didn't have a power adapter and but my other Firewire hub's adapter fit it and I stupidly plugged it in. I found out later that the second hub uses a 12V power source, but the first hub is only supposed to use a 5V power source. (I stoopidly figured 12V was gonna be OK, since Firewire is supposed to be able to provide 12V x 1.25A ideally. In fact, my other hub is rated for 12V x 1.5A.)

With the 12V adapter, the hub power light comes on normally, but the hub wouldn't provide power to anything. There is a separate light for Firewire power, and it doesn't come on. Now I've tried a 6V adapter and power light still comes on (but the Firewire light does not), but the hub still won't provide power to anything.

The hub works fine if I provide power though a powered 6-pin Firewire cable plugged into it. Both the Firewire power light and the hub power light come on.

Could I have fried it? I would have thought that if I fried it, it wouldn't work at all, or else at least I wouldn't be able to get power at all, even from a powered Firewire cable. Nothing on the board looks fried.

ie:

12V DC:
Hub power light on
Firewire light off
No power to Firewire devices

6V DC:
Hub power light on
Firewire light off
No power to Firewire devices

Powered 6-pin Firewire cable which I think is 12V:
Hub power light on
Firewire light on
Power to Firewire devices

 

[Eug]

For what it's worth, I see some capacitors on there that say 35 V and 25 V.

 

[Eug]

TTT

 

[arcenite]

Why don't you just use the powered 6-pin Firewire cable?

Bill

 

[Jeff7]

Ok, it sounds like a regular powered hub, similar to a powered USB hub. Assuming I'm reading your post correctly:
But if it needs only 5V from the power brick, and you put 12V into it, it's very likely that you've fried a lot of components in the hub; I'm surprised you've not produced a good bit of smoke from it by giving it over twice the power it is rated for.

 

[Eug]

Ok, it sounds like a regular powered hub, similar to a powered USB hub. Assuming I'm reading your post correctly:
But if it needs only 5V from the power brick, and you put 12V into it, it's very likely that you've fried a lot of components in the hub; I'm surprised you've not produced a good bit of smoke from it by giving it over twice the power it is rated for.

Yep I'm a moron. OK, I won't RMA it, since it's my fault. I should have just waited until I got the specs from the store. (The power specs weren't listed on the package and stupid me I just assumed that 12 V would be OK. I wonder how Firewire power works. The cable is supposedly 12V, but my drive needs 5V, yet the drive works fine off the cable of the other hub.)

Why don't you just use the powered 6-pin Firewire cable?

That's what I'm doing. Fortunately, I only have a couple of devices which need external power, and the power from the 6-pin cable plugged into the hub is enough to power them. But it would have been nice to have external power anyway.

 

[thorin]

Sorry to hear about your bad luck Eug but at least it isn't a total loss

Thorin