Here we go... Since I've got my grade down to F I may as well get kicked out of school.
Your secondary side capacitors are SMH 85C devices from Nippon Chemi-Con.http://www.chemi-con.co.jp/e/catalog...n-e-100401.pdf
Those particular ones are not in the data sheets. Those who do will know that 87V 4000uF capacitors are kind of like hens teeth. 80V 3900uF/4700uF seem to be the closest standard values. What's the story behind them?
This is my model playing a bit of 'club' music into 2 Ohms. This one here,http://free-loops.com/download-free-loop-7951.html
Yes I know you think there is something wrong with my model but, for the purposes, it can't be that wrong... can it? Maybe variations in loudspeaker impedance save the day.
Anyway. Trust me on the figures....
I get 28 Volts RMS for VOUT so that's 392 Watts. I think that slots in with your power figures.
Peak excursion on VDD due to supply pumping is 88 Volts. That's a bit Dude
Ripple current in C3, one of the secondary side reservoirs, is 7.6 Amps RMS. Whoops, or maybe not.
The Headline Data Sheet, and they are notorious for not giving meaningful or full information, says that 'similar' devices, page 53, have a ripple current rating of 3.5A RMS so you have exceeded that by a factor of two. Well done.
This will be FUD because you, as the engineer, will have otherwise verified things. I am sure you will have some answers.
However the 'lifetime' of these capacitors operated at their limits is 2000 Hours. [Yes as qualified by what is given as being 'out of spec']. That's about 83 days of full on techno-dub or whatever the yoof are into these days.
Try not to get upset. It's called peer review. I'm sure your customers will be reassured when you blow my comments into the weeds with an appropriate response.