Originally posted by SOldBear Why don't you measure the trigger voltage of that particular flash unit? If you don't have a multimeter, buy one. It is inexpensive and is a useful tool to have around the house.
If you don't want to buy a multimeter, bring your flash unit (with batteries of course) to a local Radio Shack. I'm sure they will help you out.
I had 3 Vivitar 283 units (all sold), one is 183V, the other two are about 8V.
You can also touch across the PC cable connected to the flash. If you feel it, don't use it.
As you might guess, I did this test by accident, but I confirmed it with a multimeter. No permanent damage to the flash or the finger.