Remove the new RAM put in the old and try again. If it turns on it's either bad RAM, bad RAM slot that won't run the larger module or it's not compatible with your model laptop.
If you want to make sure you get working RAM, try www.Crucial.com. When you put in your model to find RAM for it, the stuff that comes up is guaranteed compatable. There is a post on Toshiba's forum that the RAM is "ddr3 pc3 12800s" That s after the speed number means it's low voltage. Or should be that at least in all the other sticks I've seen with an s after the speed.
While a lot of RAM and computers that are the same type and speed (and often different speeds are also fine) work well together, some systems are more picky than others, especially computers from the likes of HP, Dell, Toshiba, etc..