How to get device out the APX mode?

I have a problem with my tab A500. It was working so good one night then after shutting off and try powering back on, the tab did not turn on. I replaced a new battery, after pushing down the power button the light come on but no vibration and screen stay black. when connected to PC it shows a message the device is under APX mode I was searching a bit. it may seem reset and power button were pressed and held the same time so device went on to APX mode. Please if somebody may has any suggestion how to fix this issue. I will appreciate. thanks