I’m no help, but I can at least bump this to the top.
Take the battery out for 10 minutes.
Does your laptop have a DVD drive? You can run a recovery disk if you have one or can get one as there are some out there on the web for download.
What happened before it crashed”
Any symptoms, changes made, dropped it?
Black screens matter
make sure the screen brightness is not set to zero.
On board Video card could be kaput , just threw one away
Remove the battery. Plug it into your wallwart.
Try this. Push in the on button and hold it in. You may see a white light flash a few times. It happens to me sometimes. Something about dumping the cache. Anyway hold the button in until the flashing stops. Let go, then press in just once like you are turning it on. Works for me.
Like someone said, if nothing comes up, even the options for Bios or the Recovery setup, it could very well be the video card on the motherboard went bad.
CGato
You might try plugging an external monitor in it, to see if your screen has died, or the video circuits have died. You can try a strong flashlight against the screen to see if it’s only the backlighting that has died. You can try running it on AC with the battery removed. (Dead battery if that works...)
You can open it up, blow out the dust with a can of compressed gas, remove and reseat the memory modules and any other easily removed modules.
1. Plug in a monitor, you might need to select it (usually a function key and a number on a laptop) but sometimes it is automatically selected.
2. Watch and see if the hard drive is running
3. Download a live linux distro that you can work from and hopefully access your hard drive. Of course you need access to another computer and a usb drive or cd. You will need to learn how to boot from alternate device.
Not the end of the world yet!
Youtube is your friend here...
Try this video troubleshooter from You Tube— black screen.
https://www.youtube.com/watch?v=chaoqoebcTo
Is your lappy POSTing? Not clear from what you said.
Can you feel/hear if the HDD spins up? If so, can you hear the drive heads thrashing about?
Can you plug a diff monitor into an aux port?
Can you remove a base cover and reseat the memory stick(s) and HDD?
Do you have recovery discs, or can you borrow a Windows distro disc to boot from? Have you updated to Win 10 yet?
Compaq?.....
After of course trying a live CD boot to see if the hardware is OK.
My Sony Vaio just started doing same thing today!
Finally isolated it as a loose wire to the screen inside the right hand hinge!
I’ve had great experiences with the Geek Squad.