How do I free up the volume control that is sticking?

This is a new feature (volume control) on the remote. See https://www.cnbc.com/2018/10/03/amazon-fire-tv-stick-4k-remote-volume-buttons-rejoice.html

See here for quick set up guidehttps://s3-us-west-2.amazonaws.com/customerdocumentation/Amazon+Fire+TV+User+Guides/Amazon+Fire+TV+Device+Documentation/Amazon_Fire_TV_Stick_with_Alexa_Voice_Remote_US.pdf

Anti Corrosive Lubricant Spray try this and see what happens.

spray your volume control with a dirt/rust cleaning cannister if you cant access it, open your spk system then spray it directly with straw stick into the cannister so that it can be easily sprayed into that volume control, hope this can help.. thanks for asking, good day..

Laptop's sound can fail to work for a couple of reasons:

(1) the sound drivers are not properly installed - as far as I know, every computer manufacturer's web site will allow you to download their hardware drivers for free. Hope you've already done that.

(2) the sound hardware in the laptop are either disconnected or failed - a small number of laptops actually use separate sound cards (instead of integrating the audio hardware on the main board). Hopefully you've already checked that, too.

(3) the audio output jack (headphone) is damaged - in which case the sound hardware is functioning 100%, but there's no sound produced due to a shorted jack.

That being said, if it's neither of the above, the cheapest means of getting some basic sound to a muted laptop would be a USB sound card and a set of external laptop speakers. If it sounds elaborate and expensive, I assure you it's not. Assuming you're running Windows (hopefully XP or newer), you can buy a USB sound card on eBay for around $2 and pay about the same price for a cheap set of cheesy laptop speakers - plug the USB sound card into a working USB port, plug the speakers into the USB sound card, it's plug and play, and ... viola - you'll get $4 worth of cheap sound. It's a bit cumbersome but it's a cheap workaround that I've done before when a laptop went mute and I had only a shoestring budget to work with...

How to Fix a PSP Volume Button through Software
Check to be sure that your PlayStation Portable's AVLS (Automatic Volume Limiter System) is turned off.
Start your PSP without a game in it. Choose "Settings," then select "Sound Settings." If the AVLS option is "ON," turn it "OFF."
Check to see that your memory stick is inserted properly if the sound still does not work. This often interferes with the volume control. Remove the memory stick and reinsert it.
Perform a hard reset of your PSP if the volume still does not work. To do this, first unplug your PSP and remove any games or memory sticks. Then remove the battery from its cavity on the back. Press and hold any button for five seconds, then reinstall your battery.
Move on to hardware solutions if none of the above options work
How to Fix a PSP Volume Button through Hardware
Remove your PlayStation Portable's battery pack, any games and memory sticks. Unplug it.
Unscrew all five screws that hold the faceplate onto your PSP. The fifth is hard to locate, so find it just below the screen on the bottom edge.
Clean the button heads underneath the volume buttons with a small cloth. You should also clean the Home button nearby as this often interferes with the volume button.
Return the faceplate and screws, and test your PSP.

Make sure that the volume + button on the front is not sticking. If it is spray a little WD40 on it and free it. Then you should have control over the volume.

if you have a cuetip and alcohol clean around the volume control it might just be stuck. Because liquid or something got on the buttons and make them stick down or stay up.

You can purchase clear 2-part epoxy products at most home improvement stores. You will also need masking tape (or similar) a popsicle stick (or similar) a small piece of cardboard and a toothpick.
Mix the epoxy with the popsicle stick and apply a small amount to the exposed surface of the volume control's stem. Holding the knob in place, run a strip of tape from the top of the unit, across the knob and to the bottom.
These epoxies are very strong and fast setting. It's probably best to leave the tape for at least 8 hours but you should refer to the instructions for the epoxy you buy.

Good Luck,
BB

Ensure nothing sticky has been spilled on the TV or the remote, causing the volume down button to stick. Remove batteries from remote to rule it out. Carefully inspect TV volume control for a sticking button. If you find it is sticking, get electrical contact cleaner from Radio Shack and spray the button. Ensure TV is unplugged first.