I purchased a bipost to vivitar cord from Paramount. I have only "attempted" to use it a few times, but in the times I have, the same problem seems to appear.
First the facts: Crown with a supermatic(x) shutter, clean bipost contacts and a used vivitar 283.
Every time I go to use this setup, I get one flash on shutter fire, and then not another. I'll put it away, put it all together again, and the same thing happens.
One flash and done.......help.

Several things come to mind. If the 283 is unplugged from the shutter can you get multiple flashes using the 283's test button? If not, are the batteries fresh? If so, try shorting across the bipost plug on the cord with a short piece of insulated wire to see if you can get multiple flashes, to see if the shutter is part of the problem How are you mounting the 283? If you put it into a solid metal shoe, it can cause it to malfunction. Need more detailed information on what you are doing and what you have tried to isolate the problem. Fred.

The test button flashes fine. I don't mount the flash, I hand hold it, so nothing comes in contact with the base. I will try the wire trick and let you know the results, Thanks for the help!!

shorting the cord with a wire produces a flash every time. Must be a problem with the shutter? Where (or how) do I check it?

The shutter is possibly keeping the contacts closed after firing the flash, preventing it from recharging. If you have an ohm-meter, you can connect it across the bi-posts to see what is happening. Is the shutter a Kodak Supermatic X, with X sync only? If it will flash the 283 once, there should be a procedure to allow additional flashes. I assume that to get the one flash, you connect the cord and then cock the shutter. Re-cocking the shutter should clear the flash contacts again and allow the 283 to charge up for an additional flash. Some of these shutters have a 10K resistor inside that may prevent the 283 from charging until the shutter is cocked. The resistor is to prevent flashbulbs from flashing, but could provide enough continuity for the 283 to prevent it from charging. After you get the one flash, disconnect the cord, re-set the shutter, re-plug the cord and see if you can get another flash. Fred.

The shutter is a Graphic supermatic (x). I tried the procedure you suggested, with the same end result. I can't get a second flash out of the unit, but the test button works fine. I will have to borrow an ohm meter to check my bipost. Thanks.

new info.........
Their is no apparent problem with the shutter. I got frustrated and did a test. The 283 will fire multiple times, BUT only if the shutter is set to 1/50 or slower. I thought these things were supposed to work with all shuter speeds? Is it syncing as with a flashbulb?

Well, that is a bit strange. However, you must remember that the faster the shutter speed, the less time the flash contacts in the shutter are making up. I would think it should fire the flash at all speeds. I mean, if it flashes once...it should do it again. Supermatic was a Kodak term, even though it has the Graphic name on it. Probably has a Kodak Ektar lens. The way I test flash sync at higher speeds is to connect an ohm-meter to the flash terminals...cock the shutter...hold on to the cocking lever...trip the shutter...and, by holding the cocking lever, let it open the shutter slowly and go through the cycle to get a good reading on the ohmmeter. You should get very low resistance at the point that the shutter is wide open, with X sync. If you try to observe it at regular speed, you'll only get a twitch on the meter. Your flash contacts may be dirty or corroded, so that the one flash, which is switching the trigger voltage, may heat the contacts and increase their resistance so that they can't perform in subsequent attempts. Try flashing the one flash at, say, 1/100th of a second, and wait several minutes and see if it will flash again. This is grasping at straws...but something logical has to be happening here. Fred.

Fires at slow speeds only, just once at faster speeds=dirty/corroded contacts inside the shutter. It should be an easy fix.
Charles

The speeds 1/50 and slower work all the time. The faster speeds are the one flash and then none problem.
I'm not real comfortable opening the shutter. If it's open clean and done, no problem. But if it's open clean, twist the little doohickey back into place reattach this, and close, then I ain't touchin it...
Some business for the local repair guy.

Simple remove the cover, clean the contacts(may require burnishing tool, fine emry cloth, or scotch brite) and reassemble. Best left to experenced shutter repair person unless you can handle tiny screws and delicate things that 1/2 ounce pressure or less can bend.
Copper or brass strips were used and tarnish is at a point simular to a moderately discolered penny. Tarnish to the extent of a heavily discolored penney won't fire a flash.
Charles

It still seems odd to me that you get several flashes at 1/50th and then only one flash every time at, say, 1/100th. Is this true?

I've got a Sunpak 383 Super (I know, different flash, just trying to provide broader information) and just tested it at all speeds from 1 second down to 1/400 and it fired fine each time. My Crown has a Supermatic X shutter as well.

I know you said it wasn't a problem with the wiring in the shutter. Perhaps a problem with your flash. Wonky wiring with it? Have you had it looked at? You said you bought it used, right? Does the Vivitar have the ability to adjust power output? If so have you tried different power settings?