Another method
If you are confident in removing the hard drive in your laptop by yourself (difficulty depends on models, some has just a screw to unscrew before you can remove the hard drive while other need the entire bottom case to be remove before the hard disk can be seen) in that case, it will be much better to assist if you share the bottom case image of your laptop here (since the model may vary depending on region, it is best to check the image of the problematic laptop itself)
If you have an internal hdd case use that to pulg the hdd into a working laptop and boot from the plugged in hdd, if it works, then plugged hdd and its content are safe and you can rule out this hdd from the part that might pose as a problem.
Update your status, so as to narrow down what might be problem. It might either be Display, RAM, or something else. If you follow these two method and see hdd working, then definitely your hdd isn't at fault.