Hi, I have a Macbook Pro 17 early 2011 which I have recently updated to OSX Sierra. I'd like to run diagnostics on the machine as it has been running slowly, but pressing D is not working. I gather I have fallen into the void of machines that are older than 2013 but have a recent version of OSX. What would be the easiest way for me to run diagnostics on this machine? Thanks in advance.