The left hand-side of my Sennheiser HD 205 headphones does not play and sound at all. Only the right-hand side of my headphones plays sound. What is the cause of this problem and how do I fix it. PLease get back to me as soon as possible. Thank you very much.

If the crackling occurs only when opening windows or another program, the crackling is not due to the headphones but to a lack of CPU resources in your computer settings.
If you are in Windows 7,

1. click the Start button , and then click Control Panel. In the search box, type Performance Information and Tools, and then, in the list of results, click Performance Information and Tools.
2. Click Adjust visual effects. If you're prompted for an administrator password or confirmation, type the password or provide confirmation.
3. Click the Visual Effects tab, click Adjust for best performance, and then click OK.

If you click my user name you will find a tip about headphones that might be able to help you.

you need to open it carfully and see if cables or one cable or broken
If the one cable its broken you need to solder it the speaker

Hi, Ian, If you have soldering experience, you might be able to replace it by yourself. If you remove the portion of the wire that is frayed and replace it with new wiring, it might work. If you feel comfortable doing this, I would say go ahead. However, it might be just as cost-effective to take it to a local audio-repair shop and have them do it. I have had multiple sets rewired myself, and it has cost less than $20 each time. Either way, it should be a relatively easy and cheap fix.

See my tip on headphones. Just click my user name to find it.

The two copper wires on your headphones are independent grounds for each channel. Twist them together and attach them to the ground cable ( black) of the new plug. The colored wires of the headphone correspond to the live wires of each channel, and the plug should have the same colors. Wiring together the grounds will not affect in any way the stereo separation, it is just that each ear needs its own ground. Cheaper headsets just transfer the ground from one ear to the other one through the metal headband.

As long as it is NOT a wireless or noise cancel type, try looking at my tip on headphones dodgy cable/plug problems.

It looks like the speaker has gone. Check with your local authorised dealer for a replacement speaker.

Turning the transmitter on and off (Fig. 5)
Turn on the sound source. This automatically activates the
transmitter and the green LED “ON/OFF” lights up. If the sound
source is turned off, the transmitter is automatically deactivated
after approx. 3 minutes (the LED “ON/OFF” goes off).
Note: The automatic level control only functions if the volume of the
sound source is sufficient.