Hi all, I hope you can help, I'm having a really weird problem with my Macbook Pro 17" mid 2010. I done a clean install of El Captain - ever since, when I start up, the date/time resets to 1-jan-2001 / 00:00 If I then set the date/time, the next time I start my laptop on battery power, when I get to the apple logo it will load a little bit then shut off. I then have to plug in the charger and it will start up again. Once logged in the date/time will be reset again. (This issue doesn’t happen if I start up with the charger plugged in). If I don't set the date/time, I can restart and boot without the charger and it won't crash, but of course the clock is incorrect - and nothing functions well without setting the date/time. Any help advice would be appreciated.