I bought a YS-90DX strobe which I think was NOS: everything in plastic bags, closed with little pieces of colored tape (strobe, synch cord, instructions, diffuser, spare o-ring, tool, and lube).
I tested it on land with a dual-strobe setup and TTL converter-N and it worked fine.
On first dive last week (80 minutes, max depth 35ft), it was slow to charge and fired erratically. I thought it was probably due to weak batteries which I changed. Second dive, yesterday, similar profile to last week, it charged right up. After the first photo, the strobe didn't fire. And in addition to the "ready" light on the off-on-TTL switch coming on, the light on the 'slave' which illuminated and stayed lit regardless of the switch position.
After the dive, I noticed some tiny droplets of water on the inside the front of the flash housing. At home, I washed, dried and carefully disconnected the strobe.
The inside of the synch cord connection and the battery compartment were clean and dry. So somehow the sealed unit flooded: I decided to disassemble it. I took apart the 2 big body parts and saw that there was a lot of corrosion on the circuit board. About a half teaspoon of water was inside. I decided to further disassemble since the electronics looked ruined. So I dissected the ports to the outside to see if I could find anything obvious.
The 3 BLUE o-rings (large for 2 body parts, medium for synch cord bulkhead, and tiny for manual stepped power switch) all seemed OK. Two small BLACK o-rings ( for the on-off switches for 'power' and 'slave') seemed OK.
The 3rd thinner black o-ring for sealing the black TTL-Slave Sensor port on the front lens had a two pieces of tiny fiber crossing it (see photos) and there was a slurry of watery lube at this site.
Do you think it could have flooded because it hadn't been used in so long? (Faulty o-ring sealing because of age?)
Could such tiny pieces of fiber caused a leak of ~ half-teaspoon of water?
Other ideas?
Thanks!
David
