Most of the time won't power up

Strange situation. Power button is ok. I removed the display, LED1 is burning on the motherboard, press power button, LED1 goes out, noting happened. Remove the battery, remove the power cable, replace the power cable, replace the battery, LED1 is burning, press the power button, LED2 is burning, computer starts, LED3 is burning. Shutdown by holding the power button. LED1 is burning. Pressing the power button again, LED1 goes out, nothing happened. Remove the battery, remove the power cable, replace the power cable replace the battery, LED1 is burning, press the power button and the computer starts. Looks like it only starts after removing and replacing the battery. Weird. After starting, no problems at all. So it's not the power supply, but maybe some logic inside? Because it will start after removing and replacing the battery? Did some further investigation, removed the small connector from the power button from the motherboard, and trying to start the computer by shorten the two pins, and let the battery stay in place. Sometimes it will work. So LED1 is burning, shorten the pins and the computer starts, but the most of the time, after shorten the pins, LED1 goes out, and that's it. LED1 only starts burning again when removing the 220V power cable and connecting it again. Strange. Any ideas are very welcome

Regards,

Mark Hofland