Could you be a bit more specific? Do you know what was happening leading up to the current problem?
I am going to write all of the following assuming you have a mechanical Hard disk, NOT and SSD. If you have an SSD some of the following information will not apply (such as an audible verification of the device working)
I am going to assume that when you attempt to power on you're still hearing the chime, which means the Logic Board and RAM are checking out okay. If you get a grey screen that means the video card is also fine (a sub segment of the Logic Board) and if you get to a flashing folder icon with a question mark then you have one of a few different possibilities.
First and easiest check would be to hold down the option key as you are trying to power the system on. If you see a blank grey screen with an icon showing what looks like a Hard Disk and the words Recovery HD XX.XX where the XX is what version of the macOS you have/had installed then you may have something going on with your main partition on your drive.
If you see nothing on the screen when pressing option try putting your ear on the computer on the right palm rest area, listen for a spinning whirring sound. it should be pretty pronounced and this will tell you if your disk is getting power, or if it is even spinning (it could have power and not be spinning, or it could not have power at all, or it could be working fine as far as the system is concerned)
If you don't hear sound you'll need one of three things. Directory repair, a new drive, or a new drive cable. The cables have been known to fail over time, due to shock or flexion (breaks in the copper) and they're easy enough to replace in both cases. If you have access to a 'known-good-laptop' hard drive to install and test with try that first, if you have the same symptoms, then its likely the cable. If you try it and it does work then its likely the drive needs directory repair or whole replacement.
Finally if you have access to a bootable copy of the OS or the OS installer you could try using Disk Utility on the recovery partition/bootable copy to repair the internal disk if its present to the system (if it can see it)