This could be related to the charger. How old is the charger and does have you tried using a different power cable/ power box? After time the hardware gets worn out and can slow down and maybe not even work at all. Has the device ever gotten wet or has anything damaged the charging port?
Do your earbuds have a built in microphone? If so try taking a video and seeing if the audio works that way. There is also a button you can press on the call screen that usually switches it from one microphone to the other. Also, make sure the headphones are plugged in all the way.
Try this: Hold down the power and home buttons to turn of the phone, and keep them depressed until the phone restarts itself. Continue holding these buttons down until the phone then turns itself back off. Wait a few seconds, then depress them again until it starts up, then let go of the buttons. I've heard this has worked for some people. I have also read about the "drop technique" where people put the phone in a case then drop it from about 6 or more inches onto a hard surface with the screen facing towards the ceiling. I wouldn't personally do this until I've tried everything else but many people have backed this technique.
I have heard of this problem before and also of a solution that works for some. Disconnect the Air pods then press and hold the Bluetooth setup button on the back of the case until the status light flashes amber a few times and then finally flashes white. Make sure it flashes amber before you release the button. After doing so reconnect the Air pods and the problem should be resolved.
Is there any blinking sequences? I had a Pavilion that the CPU went bad on. The laptop would start but the lights would flash in a certain order every few seconds. It could be possible for many things on the laptop ended up breaking. Hard drives for example can be very easily damaged by impact. It could also be the screen might just have been damaged and you need a new one. It's very hard to determine the problem unless I'd be looking at it myself or unless it's throwing some codes indicating something is bad.
If you pull up at the bottom of your iPhone and swipe to the left there should be a "Now playing on (your device)" make sure that's switched over to the speaker. If that doesn't work try pushing the play/pause button if the speaker while it's connected to the iPhone this has happened to work on multiple cases with Bluetooth speakers/headphones. If all else fails go into settings and forget the device then restart both your phone and speaker. Reset the speaker by holding the minus button and power on for approx. 10 seconds.
I found a motherboard replacement for around 16 bucks here on Ifixit, as far as just the port itself I'm only seeing stuff on Ebay and those are ranging $3-$6. Keep in mind if you plan on replacing just the micro USB port then you'll have to know how to solder the new port onto the motherboard. Here is a guide on how to take apart the controller and taking the motherboard out.
This could be a result of a connection somewhere that broke loose like the lift links not being connected. If you could give me a model number of the mower I could maybe find a diagram to help you find those lift link and connections.
This depends on whether you are planning on repairing the device yourself or if you'd take it to a repair shop. I looked around a little online and a replacement screen would cost anywhere from $20-$60. I'd have to say if you'd take it to a repair shop it would cost at least $70. I hope this helps.