Beyond the Firewire port issues

[Alan Williams]

Hi everybody,

New here and have a dilema.

I cannot log and capture anymore from my JVC GY HD100u. Initially, it was the DV footage that I was suddenly unable to capture. Then several weeks later the HDV followed and now I cannot capture anything.

I had the Firewire port replaced because it appeared damaged and we thought that was the problem but apparently it is not or there is an aditional problem beyond that.

I have read some threads that warn about not powering down before plugging in and unplugging from the Firewire port and also powering down when switching from DV to HDV. I've tried to be cognizant of that and use caution but it is certainly possible that it occurred.

In any case, can anyone enlighten me as to what might be the next component beyond the Firewire port that could have failed. Another JVC user told is a fuse for DV and for HDV and that they likely blew. If that is the case, what are my repair options?

Thoughts?

[Sareesh Sudhakaran]

Does your NLE recognize the camera?

If no, have you tried it on other systems or NLEs?
If yes, you don't have a firewire issue.

Also, have you tried the component output? Does it work? Can you record on tape?

If you can do any of the above, then your camera is basically fine. By the way, the component output of the JVC is the best (4:2:2 signal) - better than firewire or tape.

A little more specific info might help.

[Alan Williams]

As far as my NLE, it shows "no communication" on both HD and HDV capture settings. It used to work and then stopped, so, I assumed data was being prevented from leaving the deck.

We have successfully been able to extract data via the component output nand we can record to tape just fine.

When I plug into the Firestore, it no longer initiates sync with the camera and I, as I said, I can no longer capture on my NLE. I assumed it to be an issue at the Firewire port or perhaps just beyond.

I will try capturing with another system and see what happens to rule out the Firewire.

In the meantime, can you enlighten me as to the possibilty of what could be occuring beyond the Firewire port itself?

Thanks for bearing with me on this.

[Sareesh Sudhakaran]

I don't have much technical info on what goes on inside but the general path is -
[Sensor - AD - Signal Processing] -
a. Component
b. Signal processing/converter -
i.Tape Recorder
ii. Firewire port

I'm sure there are a lot more steps going on, but for troubleshooting purposes, if you can read out of your component, your main circuit from the sensor is okay. If you can record on to tape, then your 'b' circuit is okay.

This brings us down to the firewire circuit, which has the following (highly generalized) systems -

1. Port/Connection on the inside - Involving the circuitry and the connectors themselves
2. The power supply (Routed from the battery and the bad apple in this system)
3. The front-end connector and pins.

If your camera is 'detected' by ANY computer via 1394 (doesn't matter which NLE), then your #2 is okay.

If not, your firewire port is kaput.
If yes, then -
Can you get live view on any NLE?
Yes - Your camera is okay. It must a cable/capture card/software issue.
No - Your internal firewire circuitry might need to be fixed. Check the connectors on the outside and clean them if necessary. If it still doesn't work, you might want to send it to a repair guy.

[Bob Hart]

Alan.


My following comments will be of doubtful utility and should be regarded as no more than a prompt to hopefully direct your enquiries in a fruitful direction. Please forgive if I am repeating stuff you already know.

The limited times I have captured from a JVC GY-HD111, I had flaky results and several attempts for the software to recognise the camera.

When you had the firewire repaired, was there by any chance an older firmware version re-installed? The JVC GY-HD100 required a firmware update before a DR-100 recorder could work with it. An owner I know had this problem after a firewire repair.

Depending on the extent of the damage, new fuses may have been soldered in or an entire motherboard may have been replaced. An entire new board might have had an earlier firmware version loaded. This would affect whether the camera and the Firestore can "see" each other but should not affect other operations like capture.

If DV went first, HDV should have gone down with it. The firewire port moves digital info. My understanding is that it does not care what goes through. It just passes the info at a given rate per second. So I am prompted to guess that there may be other factors at play.

If my vague recollection of the JVC is correct, there is a DV/HDV-select slide switch on the right side, high and towards the rear on the camera body.

I also understand that there are menu options which also have to be selected for either pure DV or HDV to be sent out of the camera.

There may be options for transcoding the camera playback output. eg., HDV to DV. My guess is that camera record menu and VTR playback menu might have to be separately set when the camera is in one or the other of those modes.

There are layers of settings within the camera itself, DR-100 recorder and a capture computer required to be correct before the capture system will work. I was constantly getting myself in a mess with a Sony Z1 camera when jumping from DV to HDV capture settings.

I am probably unwisely putting you to an inconvenience with this suggestion. - It might be helpful in engaging the help of others, for you to post all the pages of your camera "Record" and "VTR" menu settings and all of your DR-100 recorder's menu settings. The JVC offers far more user control options but the cost is that it is less intuitive than others, needs more thorough learning by the operator and is a little harder to troubleshoot until you are intuitive with it.


As for the firewire cable :-

It has been recommended by other JVC operators that a small special jumper cable, which plugs in between the fireware cable and the camera is used. This cable apparently has only the data lines connected and isolates the two power sources, one in the camera and the other in the computer from interacting.

My personal preference is to use the thin light firewire cables, not the heavier thicker cables available from some vendors. The thicker cables are far less flexible and when abending force occurs on the cable, this is not absorbed by the cable itself but will force apart the metal shield around the firewire socket on the camera.

This shield is a significant mechanical support for the plug to keep the plug and socket mating conductors correctly aligned with each other. Once it becomes spread apart, the plug becomes unstable in the socket.

The JVC casework does not mechanically support the socket shield which has a generous clearance fit through it.

A DP I know who used his JVC cameras heavily for a living, had to use a crude in-field repair, often needed to restore the connection to his attached DR-100 recorder. This was to use ratnose pliers to squeeze the bent firewire socket shield back into its correct shape for a snug fit of the plug.

If the plug is able to slop around in the socket, the connection is not secure enough.

I ended up slipping thin pieces of plastic from an icecream container in around the shield under its rolled edge to fill the clearance between the JVC casework and the shield to give it some added strength against being spread apart. I tacked them from falling out with small beads of bathroom sealer applied with a toothpick.

You can't glue the whole thing together because the day you or a repairman wants to pull the thing apart, there is a problem.


I hope this does not send you on a goosechase.

[Phil Balsdon]

Originally Posted by Alan Williams

I have read some threads that warn about not powering down before plugging in and unplugging from the Firewire port

Hope this is a typo Alan, the recommendation is always POWER OFF before connecting and disconnecting.

The Firewire cable carries power and this can short when "hot plug" connecting and disconnecting the cables in the delicate firewire ports.