HP EliteBook 840 G4 Does Not Power On

If you press and hold the power button on your HP EliteBook 840 G4 and the device does not power on, follow this page for possible solutions.

Disconnect AC + main battery, hold Power button 30–60 s, then reconnect AC only. This “hard reset” clears latched power circuits, very common G4 fix.

Disconnect all power sources, inspect board for corrosion; clean with isopropyl alcohol or seek professional board repair.

Remove bottom cover. Disconnect main battery. Try to power on using AC only. If stable, replace the battery.