HP Probook 450 G1 does not turn off.

[warsztat]

Hi. HP Probook 450 G1 (Rampage_MB 12241-1 48.4YW05.011) does not turn off. I replaced the dead cmos battery, the bios settings are remembered, but every time I turn off the operating system, the laptop turns off and restarts after a while. The system will not wake up when there is no battery, and after turning it off I disconnect it from the 19V power supply. After connecting the power supply, I can turn it on by pressing the power button. After booting up, I unplugged the power button but the problem still persists. It's the same with sleep - after closing the lid, the laptop goes into sleep mode, reduces power consumption to a minimum (~ 10mA), and then turns on itself. I updated the bios but it didn't help. Is the 3.37V voltage on the power button correct? Is there anything else I can check? The motherboard looks good, I don't see any mechanical damage or traces of liquid spills.

[mcplslg123]

See if enable is removed from 3V/5v dc-dc converter when you shut it down. Or does it goes to zero and climb back to 3.3V when you turn it off?
Try removing the Wifi card/card reader chip/lan chip.

However, most likely its the broken dc-dc converter which needs to be replaced.

[warsztat]

DC-DC 3.3/5V is not turned off under 19V power supply because the kbc must take care of the battery.
But as you said, the problem was with the Wi-Fi card, I can only comment on it in Polish, good friend.
Ło matko jedyna jak mogłem zapomnieć to sprawdzić !

Thank you and best regards.