Try a power reset.
Remove the battery and then press and hold the power button for 30 seconds to drain any residual power from the laptop, plug in the charger (leave the battery out at this stage) and try to start the laptop.
If it starts allow it to boot to the Windows desktop, wait until the HDD activity settles then shutdown in the normal manner, switch off the charger, replace the battery, switch on the charger and try to start the laptop.
If the power reset doesn't work try removing /replacing the laptop's RTC battery to see if this restores the BIOS to a default condition. (Just disconnect the battery's cable connector from the motherboard there is no need to actually remove the battery itself)
Here is a link to the service manual for your laptop. Scroll to Sect 4-39 to view the necessary pre-requisites and then the procedure to remove the RTC battery
No data output to external video ports.
This could mean that the BIOS really got damaged bad.
All that is left is a blinking num lock LED on the top panel (which could mean something by HP hardware design, e.g. going to non-volatile storage (if there is one) to try and bring BIOS back). I left it just to let the laptop do its own recovery, but it seems like either it did not work, or there was really nothing going on.
renante palacio さんによる
Ok i have the same issue over here. Does anyone know what could help? I have the bios on my usb stick but how can i get back? There is no bootscreen so i was wondering if anyone could give me an idea how to do this?
Jochem Boom さんによる
Have you done this yet with USB thumb drive with recovery BIOS?