Speaker connections One side doesn't work when I connect phone jacks to the speakers. Does the neutrik NL4 speaker connections work Independant from the phone jacks?

It sounds like you need to get a new jack socket and replace it. It could be just a soldering problem. Especially if you have removed the plug a lot in the past.

Are the speakers powered?

Encountered the same problem. Also noticed that plugging in extension speaker solved it. My conclusion: jack output for extensions speaker normally shortcuts and is then wired to the standard speaker. If the outputchassis gets a bit bended it doesn't shortcut and then doesn't connect to the speaker anymore. Repairing is very cumbersome, therefore I just soldered a shortcut to a jackplug and inserted that.
Connecting an extension speaker apparently wires the speakers in series, instead of parallel as I would expect. In my opinion the design and construction are not very clever in this respect as jackchassis are vulnerable.

There should be a way to do that. 1st make sure speaker jack is fully inserted. If you still have same problem try normal headphones and see if there still is foreign hum- then if headphones work, check the size of both the jacks to see if there the same- you might just have wrong size jack. If that is not the problem the Impedance(ohm symbol) is probably wrong and the phone doesn't have enough power to drive your speaker.. Use a speaker with same Impedance, you might have to use a speaker with its own power supply to get appropiate volume. You could try your PC external speaker. I hope this has been helpful.

Hi taceeg06,
Have you check all the Volume setting on you computer?
On the lower right side look for the computer Icon check if there is a red X on the speaker Icon, if there is then it can be that here is something wrong with the speaker driver or it does not detect the speakers.
If you do not see the speaker Icon then the Driver for the Audio card is not installed on the computer and you may need to re install that Audio Card Driver to be able to regain the audio from your Speakers.
Also the speakers should connect to the Green Audio Jack behind the computer, if it is then still no Audio you can try the Audio Jack in front of the computer as well to check the Audio Card in the Machine, if the front and back audio jacks do not detect nor produce sound when the speakers are connected then re installing the driver for the Audio card may work, unless during the installation an error shows that the there is no audio device detected then it means the Audio Card is busted.
Let us hope not since it is very seldom an Audio Card could go busted.
I hope this helps.
Have nice day,
mvincentc

Assuming that you have checked the speaker leads for broken connections and that you know the speakers themselves work okay (test with a different amp) and that you can hear sound on the headphone socket

1. Check that you actually have the power amp switch in the right position for the outputs (monitor jacks or main neutrik/speakon sockets) that you are using (see page 25 of the manual)
2. That your speakers are connected to the speaker outlets on the rear panel and not the 'main outputs' on the front panel, which are for use with a separate power amplifier
3. Check the mute button is not in
4. You have turned both the master volume controls up.

If none of the above solves the problem it is likely that the overload protection fuses on the amplifier output stage have blown and need replacing - take to a repairer
You can find the user's manual here
http://www2.yamaha.co.jp/manual/pdf/pa/english/mixers/emx512sc_en_om_d0.pdf

First go to this site and download and install this codec pack. Also, make sure you have your speakers set as you default sound device.

JBL Creature 2 are a computer speaker system designed and sold by JBL. The system is made up of two satellite speakers and an omni-directional subwoofer. The speaker system connects directly to a computer's available sound card output jack or a laptop's stereo output jack. Occasionally, problems can occur with the sound quality and connection with the speaker system. If there is no sound coming from the speakers, check the cable connections. Ensure the satellite speakers are firmly connected to the matching jacks on the back of the Creature's subwoofer. The connections are color coded and, in addition, each speaker connector is shaped differently to fit only into one jack. Ensure the output cable is firmly connected to the subwoofer audio in jack and the computer's audio-out jack. Ensure the power button on the back of the subwoofer is pushed inward. If everything is connected properly, the green lights on the underside of the satellite speakers will glow.If there is still no sound, tap the right-hand side audio-increase button on the right satellite speaker until sound is heard. Also ensure there is audio playing from the computer. Double check the lower right-hand side of the window's main screen and look for a speaker icon. If the icon has a red slash over it, click the icon and uncheck the "mute" option.

Hope this helps

If you mean the pale green jack on the back of the monitor, it is not a headphone jack. It is to let you connect the sound output from your computer (usually also a green jack) to a little speaker in the monitor. That speaker is better than nothing, but sound quality is poor.

try to spray contact cleaner into the speaker port itself.. Powered off of course.. let it dry and try again.. this will clean any connectivity issues due to bad contacts.. as far as replacing jacks.. try the suspected "bad" speaker and wiring in another port.. if it works then the speaker and wiring is good and you have to check actual jack in which you were asking and back to auto amplifier circuit or transistors.

lorcan,  please tell us in detailed, try this, open your speaker volume to the maximum level, then touch the metal side of your phone jack which should be connected to your pc, if your speaker sound such as whistling or something that weired, your speaker should working normally. check your pc for muted sound and driver.