Hello,

Have anyone had such situation with Probook 4510s:

Motherboard with only Display, CPU and RAM connected starts, all voltages are OK but POST card stops on E5 code (if I am correct it is "Check force recovery boot"). Display remains black.
What I done: CMOS reset, Display disconnected, RAM and CPU replaced (several checked) - no changes.

Motherboard is clean, no water or liquid signs, no burnt elements. Did not find any abnormally heating elements.

Can it be BIOS chip/flash or KBC, any idea?

Cheers
/zibi

Reflash BIOS

I reflashed bios with latest available on HP page (rom.bin from the package) - no changes, still hangs on code E5.

Cheers
zibi

Finally I fixed this problem, due to 3x blinks of Caps Lock and POST E5 I checked carefully RAM sockets looking over the magnitude and found small piece of metal between 2 pins.
It made a short circuit, after removal of this metal the MB started without problems and. Display also works fine.

Cheers
zibi