White Screen and force down is not working.

Unless you go disconnecting the battery with something metallic there’s very little risk to make things worst in unplugging the battery connector. Just use your fingernails to lift up the connector. Press the start button for 10 seconds with battery disconnected and plug in your magsafe after that so we’ll see if a system reset makes the Mac return to life. White screen and dead power button is pretty unusual. Try and press the Alt button right after the machine starts to see if you get at least a boot option..in case nothing happens it would be good to have an alternate boot media to start from a usb port, external drive or usb thumbdrive with os installed..anything available ?