I need a sycn cord (patch cord) for a Sunpak 544 auto thyristor flash unit. Where do I get one, or better still, two replacements?

I found this for a Sunpak flash which is similar to the G4500dx:

Reading from the "auto555/G4500DX" Manual, you need to:
1. Slide the Film Selector to desired ISO - (that is the same as your camera ISO used - so, make sure you turn Off the Auto ISO feature if your camera has one).
2. Slide the Mode Selector to "A" (Auto position). This will be Auto Thyristor mode on the flash.
3. Slide the Auto F/stop Selecct Know to desired lens openning - ( so use your camera in Aperture priority mode, more in Manual to prevent changes in the camera aperture value during shooting)
Shoot, and be happy with well exposed pictures by the Auto Thyristor features of the Sunpak 555 flash.
The Sunpak 555 works great with Nikon D50, D70 cameras, as you can synchrinize flash practically at all shutter speeds. Excellent for sunny days to get narrow DOF, yet get any ambient light level contribution as desired.
For other cameras, make sure (watch out for) that Aperture Priority mode does not use shutter faster than the camera max X-sync speed - so Manual camera mode could be a better choice for a novice photographer.
In the manual there is also a list of accessories for various brand cameras, How to use Power Ratio in Manual mode, some advice on using wide lenses, how to care of your 555, and Specification section.
Minimal flash duration is 1/450 at full power, so you can safely use Auto Aperture up to 1/500 sec. Flash duration decreases with lower power setting, or lower auto mode need for poser, and the shortest flash duration is 1/17000th sec.

Yes

Paramount manufactures every kind of sync cords for virtually any camera and flash: paramountcords.com

The 544 connects to a camera via the PC cord (in this case "PC" has nothing to do with personal computers). The D3000 doesn't have a PC port, so you have to use something like the AS-15. The AS-15 mounts onto the hot shoe on top of the camera and provides a PC port.

You may download a copy of the manual here.

According to this list the 30DX's trigger voltage is borderline for use with digital cameras. You may be able to use it with no ill effects, or it may fry your camera. It depends on the particular unit.

When internal cells are fully charged it do not need external ones

http://www.photographyreview.com/mfr/sunpak/flashes/PRD_84012_3121crx.aspx

All photo shops hold "hotshoe to PC" adapters for a few bucks. This solves your problem, supposed you have the hosehold-to-PC cable that comes with the 544 as accessory. If not, such cable can be obtained at better photo shops or from www.paramountcords.com. You must know that the flash can be used together with your camera only in Aperture Priority or Manual mode (flash set to auto), or as a fill flash (flash set to Power Ratio mode). The 544 has safe sync voltage.

There can be more than one reasons for that.
1. Broken wire at sync terminal.
2. Electronic sync issue:
2.1. Faulty sync thyristor (CR02).
2.2. Faulty trigger transformer
2.3. Any other passive component around the previous two.
3. Broken sync lead to the flash tube.
4. Broken leads to the main terminals of the flash tube.
5. Electronic fault at main thyristor.
5.1.Faulty main thyristor.
6. Faulty flash tube.
7. Other, like crack on the PCB.
Good luck! :)
If you happen to decide to part with your faulty flash, please consider to write me first, I offer it a good home... best regards, Laszlo klaci(at)index(dot)hu

Try cleaning that front flash sensor.

Alexander
[email protected]