My hp laptop dv6305us screen is blank power light is on but screen is totally blank.

The DV6000 series of notebooks are known to have problematic motherboards. Try the below options:

1) Hold the power button down for 5 second and the machine should shutdown. Then power on again.

or

2) Flip the laptop over and switch the "lock" switch to "unlock". Then flip the release button to remove the battery for a few seconds. Put the battery back in and try to power the laptop on.

or

3) Power on the notebook like normal. Watch the Hard Drive activity light (the one that looks like 3 stacked plates), if the screen is blank and the activity light is solid or flashing, you know that the LCD screen is bad and needs to be replaced. If that light is not flashing then the problem is your motherboard and it needs to be replaced. Call HP and ask them if your model was part of a DV6000 series recall, if so your repair costs might be covered.



Regards,
Jacob

Leave the laptop on, does it make the sound it does when windows starts up but screen still blank / black? tilt your screen uptowards the light, can you see anything just slightly. If so the back light bulb has blown and they are a nightmare to fix and expensive to repair. If this sounds right to you how old is your laptop? hope this helps and please let me know