Warning DVX Firewire Port Burn-out

G

galluses

Member
A note of caution to all of those who connect their camera to a computer while everything is switched on.. DO NOT DO THIS. your computer is earthed, your camera is not, this can cause an arc which will fry the firewire pcb. Also DO NOT CONNECT your firewire cable to the computer first since it can then hold a static charge that will fry the pcb of your camera...
The correct procedure is:
connect the firewire cable to your camera while switched off
connect the other end to your computer while switched off
power-up .

I , of course, assumed that one of the benefits of firewire devices , was that they could be 'hot-swappable'.
Its cost me £418 for a new pcb in my DVX100AE (thats near enough $800) to discover the error of my ways.
I have been told by an electronics company that the above rule should be applied to all non earthed devices when attaching to earthed devices (its okay to attach one camera to another camera by a firewire cable , since both are unearthed devices).
Hope this is useful and saves you money.
 
Any idea if this would be a problem when plugging into a laptop, either with the laptop on battery power or on AC power?

Dave
 
from my understanding, both firewire and usb connectors are designed especially to protect against this by having the main jacket of the connector be longer than the pins inside it - this causes the ground to be connected first and thereby prevents any sort of issues like this (at least it should). Is it possible you had a damaged cable? The other thing you're gonna get from people is stuff like "i've been doing this for years without any issues"
either way, sorry about your trouble.. really sucks that your camera was damaged by something that's so seemingly trivial
 
This has been discussed many, many times. There's what "should be" (i.e., hot-swappable) and there's what "is" (which is, a whole bunch of people with blown-up firewire ports). It's not a DVX issue, it's been reported to happen on all sorts of different cameras, including PD170's, JVC HD100's, VX2000's, DVX's, etc.

The problem appears to be limited to when you're plugging into a computer that has a 6-pin firewire port. Which means all Macs, including laptops, and many desktop PCs. Laptop PCs are usually not a problem because they almost always have 4-pin firewire ports.

If you have the power on to both devices and plug into a 6-pin firewire port, the simple fact is that you risk blowing up your firewire port. If you have a Mac, do not hot-swap. If you are going to a desktop PC with a 6-pin port, do not hot-swap.
 
Is it also true that if you try to force the 6-pin upside-down, that it will fry the camera's firewire port?
 
I consider myself very lucky. I'm sure I've done what I shouldn't a few times, and now I'm done! Power off only, laptop or otherwise, four pins or six.
 
MiniMan said:
Is it also true that if you try to force the 6-pin upside-down, that it will fry the camera's firewire port?
Click to expand...

That'll put 30VDC on the TPA+ (one of the signal wires).

So...um...yeah, most likely.
 
It's interesting that I read this all time time and have never had this issue. I have never connected my DVX to and computer but I have done it with my cheap sony handycam hundreds of times literally with the computer and/or the camera powered. And I'm a mac user so I gues I'm one of the lucky ones. Knock on wood.
 
Barry_Green said:
This has been discussed many, many times. There's what "should be" (i.e., hot-swappable) and there's what "is" (which is, a whole bunch of people with blown-up firewire ports). It's not a DVX issue, it's been reported to happen on all sorts of different cameras, including PD170's, JVC HD100's, VX2000's, DVX's, etc.

The problem appears to be limited to when you're plugging into a computer that has a 6-pin firewire port. Which means all Macs, including laptops, and many desktop PCs. Laptop PCs are usually not a problem because they almost always have 4-pin firewire ports.

If you have the power on to both devices and plug into a 6-pin firewire port, the simple fact is that you risk blowing up your firewire port. If you have a Mac, do not hot-swap. If you are going to a desktop PC with a 6-pin port, do not hot-swap.
Click to expand...

So basically it's safe to use a 6 pin firewire port on the PC ? only with both power off, Connect the cables and then only power on PC and then DVX ?
 
thanks for the heads up, ive been connecting my 6 pin computer port and then connecting my 4 pin dvx. Ill make sure to have everything powered off just in case when im connecting.
 
if you plug the firewire upside-down in a 6pin firewire port, you WILL fry the board automaticly - Believe me I know

-L
 
So I am confused. I recently got my DVX and it came with specific instructions that say to do the opposite. It says:
"Connecting in the right order: When connecting this unit to the external device, first connect one end of the DV cable to the DV connector on the external device, and then connect the other end to the corresponding connector on the unit. If the DV cable is connected to the unit first, static may cause the unit to malfunction"

Please clarify which way I should be doing this. Thanks
 
galluses said:
The correct procedure is:
connect the firewire cable to your camera while switched off
connect the other end to your computer while switched off
power-up .
Click to expand...

Where did you get that info? In a leaflet that came with my DVX100B it says to do it exactly the other way round: First connect to computer, then connect to camera.
 
Yep, that is what the leaflet in my 100b says, as well.
Can someone clarify how to do this so we don't fry our stuff... Barry? Jan?

Thanks
 
the proper procedure for plugging ANYTHING in, would be that whatever is in the midst of being connected should have both ends off at the same time.

So whether you plug in your fire wire cable into your computer or camera first, the camera and computer should be off.

i dont do things this way, should, but dont.
 
Well, the way I work, my desktop PC has a 6-pin firewire port at one end of the firewire cable (6-pin end) is ALWAYS left in my desktop's firewire port. I NEVER take it out.

When I need to connect my DVX to the firewire, I almost always connect my DVX to the main AC power source (camera off ofcourse). While my desktop PC is on, I would just connect the 4-pin end of the firewire cable into the 4-pin end of my DVX camera & power up my camera. I've not have any issues with a burnt circuit board. Since in my country, we use a 3-pin power plug (live, earth & neutral) would that have meant that by connecting my DVX to the AC mains would have automatically grounded the camera before I plug the other end of the cable from my Desktop PC to the camera?

Andrew
 
That's the best advice I've heard yet. I learned that on the hard way too. I replaced a whole motherboard because of damaged FW ports.
It didn't happen the first time I did it, or the second, so I thought is was fine, but somewhere down the line..... POOF! cha ching! instant $300.
look on my face..... priceless.
 
andybiz_2005 said:
... Since in my country, we use a 3-pin power plug (live, earth & neutral) would that have meant that by connecting my DVX to the AC mains would have automatically grounded the camera before I plug the other end of the cable from my Desktop PC to the camera?
Click to expand...

Absolutely not! look at the other end of the cable, where it plugs into the charger - it's a 2 pin "figure-8" plug, thus has no earth.



The correct proceedure for connecting 1394 devices is to have both ends off, plug in, power up host, power up guest.

In reality, with a 4-6 pin cable such as is commonly used with pc/mac to camera, you will be fine leaving the PC powered up, so long as the DVX is powered down when you plug it in.
I keep a long cable plugged in all the time on both PC and Mac, and I've never had any problems.

The design of the Firewire cable is such that the grounded shell makes contact first and safely sinks any static or other voltage differenial between the devices.
 
SO, can someone (ie Barry) confirm this:

1.) Firewire 6pin plugged into computer, it should be ok if computer is powered up
2.) Firewire 4pin plug in to camera, CAMERA MUST BE OFF
3.) Power camera on
4.) When done, power camera off, and disconnet 4pin plug from camera. It is ok to leave 6pin side plugged into computer, and to leave the computer on, so long as the camera is OFF when plugging it in or unplugging.
 
1. Plug 6pin to computer. No matter if comp is on or off.
2. Disconnect camera from mains (adapter)
3. Plug 4pin to camera
4. Connect adapter to camera and turn cam on
5. When done turn cam off and remove adapter
6. Unplug 4pin from camera.

I've burnt my camera's firewire just becuse between camera "ground" and computers "ground" was AC 30 volts. Not much but enough for firewire sensitive pins. Usually plugs are designed to connect grounds first but there's always risk that this "ground difference" goes to signal pin. Same thing with computer's videocard -> TV connection.
When camera is battery-powered there's no voltage between "grounds" no matter if its on or off.
This is well-known ground loop.
 
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