I put a 9v adapter into a 5v external DVD drive while it was connected to my laptop via USB.
The DVD drive is "dead" (not the problem) .... but my ***HP EliteBook 840 G2 doesn`t power up at all.***
***I`ve tried powering up with just the battery.(no joy)***
***I`ve tried powering up with just the power adapter.(no joy)***
***I tried a few forums offering basic advice (press power button 15 - 30/60 seconds etc.)***
***This didn`t solve my issue ... so here I am ... asking the experts.***
***IS THERE A SOLUTION TO THIS WITHOUT GETTING OUT A SOLDERING IRON?***
***TIA***