Can not turn off T800

I have searched the Internet and found many suggestions but can't find one that will work for me. Here is the scenario. I was installing a theme zip file (avenger theme for IronRom) which I have none in the past with no problems. I wiped the cache and dalvik like normal. After booting up the screen gets stuck at "android is updating, starting apps" and after it runs for a while the screen will go dark but the tablet is not turned off. I have tried to hold the power button down for a looong time but it will not turn off. I have tried all the button combinations I know to boot into recovery but no joy there. I can get to the page where it shows the battery charging and I can get to the page with the yellow writing and yellow triangle where you push the up button to go to the odin download page or the up buutton to restart. When I press the down button to restart sometimes I will get the home screen with the notification that the "System UI has stopped" I will press the ok button but all it does is allow the notification to flash. I no longer have any more ideas other than to use the reset hole on the side but I am not sure what it will do plus I have a 64gb sd card inserted with about 40gb worth of data on it that I do not want to lose. Since the tablet will not turn off I can not remove the card. What can I try other than opening up the back and disconnecting and reconnecting the battery., I have never done it.