Sea & Sea YS 90 Duo Auto only fires once

I received a YS90 Duo that I cleaned up (the contacts showed some corrosion) and tried. It turns on, I can fire it reliably but not the way it's intended:

The idea is to pass it on to someone who uses a TG-6, so I tried with that camera, using a fiber optic cable.

According to the manual it has a switch: Auto 2, Auto 1 and TTL, then it has another switch for Slave ON/OFF and a third switch for the output power.

Slave is clear: ON.
Auto 2 should be for cameras with preflash, Auto 1 for cameras without preflash. With the TG-6 it worked on both but the correct one would be Auto 1 since I don't use preflash. 
Now when it's on Auto 1, I can only fire 1 flash. After that nothing happens, even when the ready light is on. If I flick the switch back to Auto 2 or OFF and back to Auto 1, I can flash again. Any idea if I do something wrong?
On Auto 2 it kept flashing but that's not the right mode. 

Besides that the flash output seems always the same, no matter what I set on the strobe. ( I tried this with another camera in manual mode to check if the exposure changes and could not see a difference).

Any thoughts? Am I doing something wrong or is the strobe broken? Wouldn't be surprised, it came out of a long storage from a diveshop that moved.

Can you confirm the strobe model? From your description of the controls it sounds like you have a YS90Auto.

Based on your description it appears to be working correctly. YS90auto is not capable of TTL as an optical slave.

The strobe says YS-90 AUTO and then smaller: TTL/AUTO STROBE Duo.

Yes I agree that it should not do TTL as an optical slave but I should be able to manually set / change the flash output using the dial that goes from 2 to 22?!

Whatever I set it to, the output is the same. No matter if I'm on Auto 1 or Auto 2. On TTL it doesn't fire at all (and of course it should not, according to the manual).

I do not have one of these so can only conjecture...

It is not a TTL nor a MANUAL strobe. From the manual it appears to be  "pseudo ttl" i.e. "auto".

What camera settings are you using?

I am unsure what S&S thinks auto means, but I am interested as I have a few other S&S auto strobes in a drawer. I thought they might be TTL as they do not have a control knob?

From my reading of the manual it seems like this strobe is designed to mimic the aperature setting of your camera...

Worst case I might take it off your hands for shipping (if shipping is cheap ish....)

Cheers

I tried to trigger it with sync cables (only fiber optic, not 5-pin), different cameras, different modes and another flash.

In my last tries I couldn't get it to fire at all but the ready light was always on. The flash-output control knob never did anything so I decided to open it to look at the thing. When I read 330V on the capacitor I decided to leave it. There is also corrosion inside the hosuing, so I think it's done. 

 I'm in Honduras, you can have it but you need to pick it up. lol.

Roatan or Utilla? Put it on a shelf. We could drop by some time when this stuff is over...

Roatan. Let me know when you get here. The Bay Islands still do not have any reported virus-cases.