Hello John Doe……I am just finding this thread now….this date….Oct 23 2018
Were You ever able to fix your HP laptop problem?
Mine was doing exactly what yours was doing.
Mine showed the charging LED from orange to white at rear left and that it saw the Hard Drive present LED on the rear right upon power button pressing.
I got mine to work………. I powered all down ( AC and battery)
I open the back cover and pulled the screen connector off near the fan and connected an external monitor out of the HDMI port. It fully powered up when connected this way and works fine but when you reconnect the laptop screen it loads down the supply and will not power up at all…..black and dead !!!
Again i disconnect the laptop screen and reconnect the HDMI monitor and it works fine.
I will be purchasing a new screen for this excellent HP red bullet !! (aka 15-af039ca)