dv7 2185dx black screen caps and num block turned on and do not blink

Hi, my dv7 2185dx laptop is turning on but the display is all black and the num and caps lock lights are on but do not blink.

This issue occured after i was reflashing the bios while the hdmi cable was connected to the tv. The process halted and the machine was unresponsive for a long time. After 15 minutes of the machine being hang up i tried switching it off using the power button but it had no effect, so i removed the battery.

Now the laptop starts but these lights are turned on without  blinking(this code is not documented). I tried using the windows and B keys pressed while turning the laptop on, this makes the lights not to turn.

I also tried the hard reset (pressing the power button for 30 seconds).

I tried removing the cmos battery and no effect

i removed the memories and hard drive and also no effect.

Is there a way to hard reset the gpu?

Any ideas?

Thanks!