ALERT: Power OFF before changing Firewire or switching HDV/DV

[John Mitchell]

Originally Posted by Carl Hicks

John,

It absolutly does have something to do with 4 pin vs 6 pin. The 6 pin FW connectors and cables carry DC power from the computer to the other end of the cable. It's this power that can cause problems when hot-plugged or un-plugged, or the end of the cable is started into the device backwards, even if not fully seated.

Regards, Carl

Carl I was aware of that but I believe whether your computer sports a 6 pin or a 4 pin socket the advice from JVC is don't hot swap in any case. If it was purely a matter of the 2 power lines carried over firewire then why would JVC not just electrically isolate the positive from the rest of the plug? Of course putting plugs in the wrong way round is never a good idea. And other users in this thread have said they have managed to blow up 4 pin ports on other cameras.

[Maat Vansloot]

John Mitchell et al--

Boy, do I have a newbie question! How do you "put plugs in the wrong way"? Firewire plugs are shaped sort of like an elongated baseball "home plate" (kind of a "V" shape on one end, and rectangular on the other). There is only one way that the plug could fit, right?

You don't mean the plug on one END of the cord is different from the plug on the OTHER end, do you? Both ends of my Firewire cord appear to be identical, male, 6-pin plugs.

[John Mitchell]

Originally Posted by Maat Vansloot

John Mitchell et al--

Boy, do I have a newbie question! How do you "put plugs in the wrong way"? Firewire plugs are shaped sort of like an elongated baseball "home plate" (kind of a "V" shape on one end, and rectangular on the other). There is only one way that the plug could fit, right?

You don't mean the plug on one END of the cord is different from the plug on the OTHER end, do you? Both ends of my Firewire cord appear to be identical, male, 6-pin plugs.

Maat - don't panic! both ends of the six pin cable are identical.
It is possible because of the poor design of the 6 pin plug to partially insert it into a socket the wrong way around (especially in the dark behind a computer). That is what Carl is referring to.

[David Scattergood]

I'll add that the firewire port I blew on my previous camera (Panny) was a 4 pin.

[Maat Vansloot]

Originally Posted by John Mitchell

Maat - don't panic! both ends of the six pin cable are identical.
It is possible because of the poor design of the 6 pin plug to partially insert it into a socket the wrong way around (especially in the dark behind a computer). That is what Carl is referring to.

Thanks for your answer. I think my panic was mostly because I couldn't quite see how the plug could be inserted the wrong way around---- and I certainly didn't want to try it and discover for myself!

The plug and socket design do seem a little poor, don't they? Pretty darn loose, too. Why not some kind of twist-lock like a BNC?? Anyway--thanks again.

[Jerry Jesion]

I burned a GL2 hot swapping directly to my computer. Canon fixed it under warranty but I got really paranoid about connecting it after the repair. Shutting the computer down to connect the camera was a real pain. I then purchased a Canopus ADVC100 and discovered that the 4 pin FW connector on the front was not a pass thru. I connected the Canopus 6 pin to the computer 6 pin with the power off on it and the computer. Now I just turn the Canopus and the camera off to make the 4 pin to 4 pin connection. Never had a problem since.

Just an observation: IIRC USB also supplies power and I have never heard of anyone having problems hot swapping USB devices.

Regards,
Jerry

[David Scattergood]

Jerry - I guess using the Canopus ADVC100 would be like me using the Kramer Firewire Isolator - it's far from ideal rebooting the computer every time you wish to connect the camera.

Bit of info on the Kramer PT-1FW - (Spark-Guard Pro DV Line Protector)

The Kramer PT-1FW is a tiny device - installed between two cables - that solves a huge problem in DV studios (or in any other professional or home DV application). Often - when connecting a "live" DV source to a receptor - an electrical potential difference or any other element creating high voltage (such as ESD or a live chassis) may cause permanent damage to one or both of the connected devices.


This high voltage may be seen as a spark occurring at the instant of connection, or may not be seen at all, but nevertheless it can result in costly damage. The PT-1FW is installed between two cables; does not need a power supply; and suppresses all transient high voltages down to the permitted level. It is a "life-saver" for studios and other DV applications using the 6 pin Firewire connector.

[Warren Shultz]

That's apparently how I blew my HDV firewire--fumbling to plug the cable in, I touched it upside down. It is easier to do than you'd think. I'd have to say I'm now a believer.

[Earl Thurston]

Some FireWire PCI cards use a spare floppy drive power connector to source their pass-through power. All I had to do is disconnect that to disable power out the 6-pin port.

(Of course, now I can't recharge my iPod through FireWire anymore, but it's a minor inconvenience compared to potentially buring out the HD100.)

[Maat Vansloot]

Both the Kramer line protector--

Originally Posted by David Scattergood

Bit of info on the Kramer PT-1FW - (Spark-Guard Pro DV Line Protector)

http://www.kramerelectronics.com/ind...sp?name=PT-1FW


--and the port isolator mentioned by Carlos--

http://www.abelcine.com/store/produc...cat=252&page=1


sound like handy things to have even if you are consistently following JVC's instructions for connecting Firewire.

But they are different devices (and different prices) and I'm horrible with engineering so I don't understand which is more appropriate/desirable. Can anybody give a little info on these?

I also could not easily find a place from which to order the Kramer in the U.S.

[John Mitchell]

Originally Posted by Maat Vansloot

Both the Kramer line protector--http://www.kramerelectronics.com/ind...sp?name=PT-1FW


--and the port isolator mentioned by Carlos--

http://www.abelcine.com/store/produc...cat=252&page=1


sound like handy things to have even if you are consistently following JVC's instructions for connecting Firewire.

But they are different devices (and different prices) and I'm horrible with engineering so I don't understand which is more appropriate/desirable. Can anybody give a little info on these?

I also could not easily find a place from which to order the Kramer in the U.S.

I'm not sure the port isolator would do the job (it sounds to me like it only tackles power and not static or earth potential differences - hence it is a six pin device). Kramer (who make broadcast equipment like routers and switchers) seem to have better technology built in to actually inhibit any transients. No doubt they are more expensive :-(

[David Scattergood]

The Kramer PT 1FW was about £70 - pricey but when considering the cost of what it is protecting, money well spent I reckon.

[Maat Vansloot]

I actually ordered one of the Kramer spark-guard boxes a few months ago. I think it was from B & H.

It didn't work. It didn't seem to pass the signal. I called Kramer about it and left a message; got a return call left on my voice mail and it was garbled and impossible to hear.

I have not had time to contact Kramer again and find out what was going on--I just returned it because apparently (maybe) the thing doesn't work with HDV HD signals--only DV stuff.

That's really only a guess, but you may want to watch out for this if you buy one and you are using an HD100.

[Brian Luce]

i'm always flipping that DV to HDV switch while the camera is ON. And I plug the firewire into the camera with the camera OFF but the computer ON.

No problems so far.

[Carl Hicks]

Originally Posted by Brian Luce

i'm always flipping that DV to HDV switch while the camera is ON. And I plug the firewire into the camera with the camera OFF but the computer ON.

No problems so far.

You're playin' with fire! (pun intended)