I played some high music and the left speaker stopped working but if i take of the grill and touch it, it work but when i take my volum up it stops again, z-230,

Check all your speaker wiring. Plus make certain the speakers are in good working order, and that low ohm speakers are not connected to it. For example if the unit says 8 Ohm, don't connect 4 to 6 ohm speakers.
If that doesn't solve the problem there's a fault in the main power amp.

Where do you plug in the phones? if it is an iPhone. the music playing will be stopped, just to precent your ears to be damaged. When plugging in headphones, while the volume is high, the sound level can be so high, you can damage your ears. Yes damage that will last the set of your life, because loss of hearing, can't regenerate. For that reason some MP3 played, cill stop music playing, as soon as a headphone is plugged in.
Just start the music that was playing when you did lower he output volume if the music stops.

if the unit completely stopped working try connecting the speaker to the working speakers connection, if it still doesnt work then you have seized the speaker, basically the driver is shot and the speaker is dead. you might have a warranty but usually you can smell the burnt coil. turn down the gain and the frequency on your amp as it is not properly tuned and will cause dame like this as well. if you are not certin take the car to a install shop and have them tune and balance you system for you.

check if left speaker is shut off /connections one speaker my be on a side the other on b side check all speaker connections

Does it stop on both channels? It sounds to me like the safety circuit is activating. This usually happens when either the volume is too high, or the speaker load is too great (i.e. usually loads less than 4 ohms will do this) or, the amplifier has an internal short causing the amplifier's output stage to become un-balanced. Does the sound come out nice and clearly through both channels? How long does the receiver play before the sound stops? How loud are you playing the music when it stops like this? If the sound is reasonably clear through both channels at regular volume, then there is probably nothing at all wrong with the receiver's output circuits. If the amplifier is being played at regular volume or even lower volume for quite a while and then quits, perhaps the receiver is getting too hot and it's thermal sensors are activating the protection circuit. Make sure that when you operate the receiver, that there aren't things laying on top of it blocking the unit from venting and cooling properly. Make sure it has plenty of breathing room - amplifiers (most of them anyway) are inherently subject to producing heat. If the amplifier only quits when played at high volume, well then that's probably the problem - it's probably not meant to deliver such power that you're asking it to - especially if you're driving a heavy load such as 4 ohms or less. If you're running several speakers on this unit, try scaling back to just two speakers for now, and make sure these are 8 ohm speakers. Play the unit for a while and see how it does.

My guess is it's a faulty upgrade, unless you aren't adjusting the volume after you take the headphones out (when you take headphones out, music stops, and the volume changes).

Try restoring it. If it still isn't working after that, try re-downloading the os 3.1.1 update. It could just be a corrupted file, and it does sound like it.

Your speaker volume must have reset. You have to touch the dots on the right speaker to turn up the volume to desired volume. I just remembered that on my system. Hope this helps.

Right click the volume control - select open - this will open a larger volume control showing the volumes for each type of sound. Make sure none of the sliders are muted or low.

Ok this might be caused either by drop of voltage available to the player or by physical vibration of the disc disabling the laser lens to focus on the surface of the disc and read the data. You may diagnose this yourself. Play the same music rising the volume level, until it stops playing. Note the level. Turn on lights, blower and heated seats if you have them and do the same test. If on the second try, the music stops playing earlier-on lower volume level than the first time, you have a problem with your wiring or your alternator, because the car does not have enough power for the unit to keep playing as it is sending too much power to other appliances. If on the second try it stops at approx the same volume as it did on your first try, it means, that your car stereo vibrates too much for the lens to focus on the disc. You may try fixing your speaker setup tighter in the car chassis/door frames. You may also take the JVC unit out of the dash and mount it somewhere further from the speaker-induced vibration.