I have some Vivitar 283 flashes I used several years back in lower power
mode for a special application (I swapped out the thyristor for a
circuit that allowed 1/16th power). The flashes were controlled as
slaves (using Wein peanuts) from my main camera, a Canon Rebel at the
time. The flashes performed flawlessly for the few weeks that I needed
them and then stored away.

After about 5 years and recently, I brought out the flashes to use now
with my Pentax KX for macrophotography and thought they would be ideal
still at 1/16th power. They started off working ok again as slaves with
the peanuts, but have quickly become erratic and I don't know why. Not
just one, but all of them after just a couple of days of use. What's
generally happening is that they won't trigger from the main flash. I
suspected the peanuts and swap them out, but they still won't respond.
I used contact cleaner on the peanuts themselves, then carefully
inserted into the 283's, but this didn't help. Also, even if I push the
ready light button on the 283's, they won't fire. Sometimes the ready
light is flashing, sometimes steady but doesn't seem to matter.

I can hear the whine of the flashes, mostly steady but in some cases
pulsing as the light flashes. Nothing matters though as any/ all of the
flashes won't flash. I've swapped out batteries for others, used the DC
to AC adapter for the flashes, and mostly they won't respond or very
erratically.

Any ideas what's going on? I do notice that if I short the hot shoe
terminals, nothing is happening on any of the flashes. I can sometimes
get them to fire if I keep bending them, but not always.

Any help for these 283's or time for something else? I'd hate to lose
all 3 of them, but none of them seem to want to work properly.