Yikes! 2013 DB9 Volante Roof issue.

Hi Aston people. Yesterday, as I pulled into our garage, I hit the switch to put the top up. This is pretty much a daily occurrence, only this time, the roof got about 1/4 the way up and stopped. I tried the switch in both directions, and nothing. I immediately knew I had a problem because the dash warning message confirmed I had a problem! With the assistance of my wife, I managed to manually get the roof all the way up and locked. Btw, is it just me, but asking my wife for even the slightest help with my car, is so belittling……after all, what could ever go wrong with an Aston Martin right?! The car I just had to have….. all the time reminding me how her Volvo never breaks. I digress: The logical thing to check first would be the hydraulic fluid level in the reservoir. Herein lies my problem: Where is the reservoir?! I believe I’ve watched every YouTube video on anything remotely connected to AM convertible tops. Not a mention other than it’s a bear to fill. While my wife and I were dealing with the top, with the aid of a flashlight, I tried to see if it was buried deep in the bowels, but still nothing. I’m sure hoping one of you can help. Any further advice on possible causes of the roof failure would be gratefully welcomed also.
Tootle-pip.