The left speaker is not working. only the right speaker is working. can anyone describe how i can open the case and inspect the headphones myself?

This unit is a powered speaker and what you are describing sounds like a bad connection or component in the amp. some parts can get hot and lose the connection on the amp board or the power board. It could also be a failed component

That might be why she bought new ones. Its usually in the plug or the left bud, check your balance on your device.

Is the sound on both channels on a pair of headphones? If it is suspect a faulty headphone socket, especially if the speakers are cut out when the headphone jack is inserted - normally.

check the balance level on the source device whether it is not shifted to the right should be in the centre with equal distant from both the sides if not then your headphones speaker or the wire connecting to the source device might be faulty.
To avoid a headache with soldering finding a speaker or wire i would suggest to buy a new headphone as they are not that much costly if you really wish to get the current one repaired then in that case either go to a technician like a audio/video repairing service centre or if you wish to do it your self then you should have two most important things 1.Multimeter 2.Soldering kit with all components screw driver take the headphone and remove the cushion of the headphone's side which is not working.You will find 3 -4 screws unscrew it with the help of screw driver and now set your multimeter to ohms postion and then touch the terminals of the multimeter with the + and - of the speaker inside if you see a deflection then the speaker is all right if there is no deflection then in that case the wire is faulty.get a new wire or try to find a old one from old stuffs carefully solder the wire to the speaker left and right{you will have to open in the same manner} and replace it your headphones will work if it is the speaker only locate a old speaker from some old broken video game/pocket transistor and test it if it shows deflection then replace the faulty one in the headphone with this one and your headphones will work ....fine enjoy...

Hi,,in most cases what causes one side of the headphone to work is because, the wire that is connected to speaker inside the headphone might have cut and it's not contacting properly.

What you will need to do is to open up the head phone (left),and check if the wire inside has not cut, If it has removed ,then you will need to put it back with soldering iron and a lead...

But if the wire inside has not removed and they are intact, then you will have to replace the left speaker .

Hope that helps...

Thanks for using fixya...

Worse case scenario is that your left speaker is gone but usually what happens is a break in the cable someplace.Are you using the 1/8" plug or are you using them with the 1/4" adapter. The 1/4" adapter might be worn out but is easily purchased and replaced.The cabling from the plug runs into the left can and from there splits into left and right speakers. There will be a wire that follows the head band under the cushion from left to right. With these headphones there is a swivel above the can and the problem might be in there. Half the problem is getting at the wiring to test it. Usually the plate that the speakers are mounted on is screwed to the back cup and the screws can be reached by removing the earpad. You will need a volt ohm meter to test the wiring. You can also test the speakers with it. Unfortunately most plugs on headphones are molded onto the cable so you will have to start by testing from the plug to the left can. Inside the left can will be a junction point where the main cable feeds the right speaker. Test up to there for right and left and if the connections are good then test the speaker. Hope this helps.

Koss has a no questions asked guarantee on some of the Pro-4 series, all you pay is shipping. Call the repair department to check.

I think I have it. I've only had a chance to listen to a couple of songs till the brand new headset's right ear died. I took it apart and found that when I hook up another speaker in parallel with the dead one, it works, which can only mean that the circuit is fine and the 'dead' speaker is really dead. No idea where to get a replacement though.

A couple of years later, but maybe this will be useful to someone:
1. Disconnect the cables (input, power, 2nd speaker).
2. Undo the two screws on the base of the casing.
3. The two knobs can be pulled off. Underneath there are two nuts that hold the spindles to the casing. Undo these.
4. The fabric cover is a push fit. Prise it off the front. If needed, use a (non-metal) tool that won't damage the plastic casing.
5. Under the cover, the two top holes contain screws - undo these.
6. Four screws hold the actual speaker to the casing. The two lower ones are slightly longer and also hold the casing together. Note this for reassembly.
7. You can now gently part the front and rear parts of the speaker housing.
8. To completely separate the parts, you need to disconnect the red and black wires that go the the speaker. The are push fit 'spade' type connectors - a tight fit, but removable.

My problem is similar - loss of left channel. I think the problem is in the headphone socket as wobbling it or inserting non-conducting objects can temporarily restore the channel. These sockets switch off the speaker when you plug in the jack, so I think the switch is faulty. I plan to desolder this part to inspect, repair, replace or bridge the connection and do without the socket.

Hope that helps.

Im sorry to say so, but the fact that speaker can still monitor volume has nothing to do with its disability to produce sound. Im not a speaker wiz, but I can think of two possible reasons for what happened: 1. something has broken inside the speaker. in this case you will have to get it fixed\replaced. 2. some disconnection accured from the hit, a wire got teared or loosed. in this case, you might get lucky. open the speaker, and search for any torn wires. if you are handy you may be able to weld, replace, etc.