I have 2 x S-2000 on my rig, and my wife one. On our recent trip to Asia, 2 of them failed suddenly on dives. First, one of mine stopped working, and a week later, my wifes gave up. Luckily a friend of ours had both an Z.240 and one S-2000, so we survived borrowing one....
I shipped both to Inon, Japan, for repair, and got a mail back, were they found out both PCB's vere "fried" due to too rapid firing sequences, with a PDF file describing the limitations. They offered to repair, and stated the cost.
I must admit I had never read this Operational Limitation document, but, from my EXIF data, I can not find that I have been shooting beyond the limit....so I think it's a bit unreasonable.
Just want to inform others that there is a limit....and enclose the document from Inon.
I am so far satisfied with Inon's service, and it is after all worth the repair, as new ones costs fairly more, and the 2 who failed have only been been used for 30 and 60 dives. They were both bought used, but was in very good condition, (one looked just like new, no visible scratches at all).