Built-in speakers problem!

Few things.
If you are talking about the built in speakers, make sure your volume is turned up. And make sure its turned up when the headphones are not plugged in. My android tablet has individual sound profiles so while I might have the sound muted when the headphones are not plugged in, if I plug them in, the volume jumps to my set level because that's where I turned the volume up to last time the headphones were plugged in. I've also had two tablets that the speakers went out completely on that to is a possibility but if you are talking about the built in speakers, check the volume levels first. You can get to them in the settings menu. Its worth noting that plugging anything into the headphone jack will "turn off" the internal speakers altogether.

If you are talking about external, plug into the jack speakers, on a tablet, you're going to need a set of powered speakers as that jack is not going to produce enough power to drive an un-amplified speaker. Make sure you are using a pair of speaks that plug into the wall such as PC speakers.

Second, if you are using powered speakers and still not getting any where, look at the jack end of your head phones and compare it to the jack end of your speakers. I know iPhones and other Apple devices have an extra connect which is why the Apple head phones all have an extra ring. My older headphones are worthless in my iPhone because they lack said extra connection. It's possible your tablet also requires the newer connection and the headphones have that while your speakers don't.

Broad answers, but I couldn't tell exactly what we were looking at based on the questions. Hope it helps, and good luck!

Headphone socket is pushed in too far, need to hook the end of the socket inward to contact the speakers when headphone is not used.

there is a black headphone jack just above the green one... try that one. also, try to plug in the jack and then turn on the monitor...

The headphone jack on the TV has switch built-in to kill the TV speakers when headphne jack is used, you need to use powered PC speakers with headphone jack and connect this PC speakers to the Audio line out of the TV set (RED and WHITE RCA audio line out). Basically the powered PC speakers are being used a headphone driver. Or you can get one of those wirless headphone system instead.

You can get a set of speakers that has a headphone jack on front (it will shut off the speakers when headphones are in) or you can unplug the speakers and plug in the head phones. Some PCs have a red and green jack in front - plug in headphones to the green, you should have the speakers shut off till you unplug. All else fails they make a headphone/mic extender that sits like a hockey puck on the desk, has cables to the mic and speaker jacks on back of the PC and on the puck part has a jack for speakers, mic and headphone - some switched manually by you, some switch when the headphones plug in. If you had posted the model I could see if your machine has front red and green jacks.

The lit indication ("amp bars") proves that the aduio signal is getting through the unit's circuitry @ least to that point; lack of sound @ the spkr & headphones indicates the amplifier portion of the circuitry is either inoperative or disconnected from the load (i.e., either the speakers, or the headphones). A common cause of this type of problem cropping up unexpectedly is the headphone jack itself; in most products of this type, the audio path from the amplifier output to the speaker connection runs through the headphone jack, so the the speakers may be "turned off" when the headphones' plug is inserted into the jack. If the unit's owner uses headphones regularly, the most common problem to be found with the jack is loose solder connections to the printed circuit board's traces from the jacks' lead(s); in units with this problem whose owner's irregularly use the headphones, it's more common to find oxidization of the electrical contacts within the jack itself.

There is a contact inside the jack that is closed when the plug is inserted. Apparently this is no longer happening. This should be an easy repair for a qualified technician.

If the rest of the laptop works and you can still hear audio through the headphones. Buy and replace the speaker:
https://en.accessoires-asus.com/?gclid=EAIaIQobChMI27rs6-ba2AIVDrvtCh0y-wwhEAAYASAAEgLRbvD_BwE
If not it might be the power supply and that would explain the jolt and the red beam.

I took a safety pin and put it in the notch inside the headphone jack input. notch is located at 12 o'clock about 1/8th inch in, (this is an important step, other steps are no good until red light is off) the red light went off (Be patient this step may take time) still no sound, I then went to Audio MIDI setup (Should be located in Applications/Utilities), go to Audio in menu bar (at very top of computer screen) and selected 'open Aggregate Device Editor,' clicked on the + to add a device I then had a few options show up in the lower [Structure] portion I clicked on all the 'Use' boxes and the built-in output bubble selected done. I then Selected Configure Speakers in Audio MIDI setup and I can test my left and right speakers individually, they put out a fuzzy test sound, pressed done when finished. They still didn't work so I set Default out put to the Aggregate Device I created, then turned on Itunes and it was working fine I just could not control the volume from the F3, F4, & F5 buttons so I went to sound in system preferences and made sure the built-in Output option was selected. I was then able to control the volume. The red light in headphone jack input may come back on if anything is inserted inside, just mess around with the notches inside till it goes off. Hope it works as well as it did for me. Good luck and please feel free to quote me and share this solution with others.

Yes, since the Headphone pin is stuck in the Jack, you are not getting audio from Speakers.

You should have noticed that connecting the headphones to the Jack will block the audio coming from the Speakers and the same is the current situation.

You can either try removing the blocked part using a Tweaser or get it repaired.