Tr140 transmitter. Hi there, we can't seem to turn off the headphones. On and off button doesn't work and there is permanent "white noise". Help please ....

No it isn't normal. This is a set that you plug into the television and it transmits the signal to the wireless headphones. It sounds like the transmitter unit is picking up interference. We can test it! The headphones can be connected directly with a wire. Try that on the television earphone jack, or on a cellphone, a radio, MP3 Player or a computer audio jack. If the audio is clear, with no hiss, then you know the problem is the transmitter unit. Move it as far away as the wires allow from the television and anything electronic.

It is advertised here on Amazon and the diagram shows how it can be connected, 4th image down on upper left.

5-in-1 Wireless Headphones Headset MH2001 MP3 MP4 ...

Amazon.ca https://www.amazon.ca > Wireless-Headphones-Heads...

5-in-1 Wireless Headphones Headset MH2001 MP3 MP4 PC CD DVD Audio TV FM Radio-Listen to Music, Chat Online & Monitor Other Rooms! : Amazon.ca: Electronics.
More here regarding the hissing sounds

https://www.google.com/search?q=mh2001+wireless+headphones+hissing+sound

Instructions
1
Set up the transmitter. Wireless headphones rely on a transmitter that sends audio via infrared or radio waves to your headset. Use the digital audio output (coaxial or optical), RCA outputs (red and white) or headphone jack on your TV to connect the transmitter. The connection will depend upon which outputs are available on your TV and/or the transmitter.
2
Use an RCA-to-headphone adapter. If you don't have a headphone jack on your TV and the transmitter includes only a headphone connection, connect an RCA-to-female headphone connector. This will allow you to plug the wireless transmitter into the female headphone end and then hook the RCA ends into your television's audio outputs. You may also need a 3.5 mm (mini jack)-to-1/4-inch adapter if the headphone plug on the transmitter doesn't match the television jack.
Read more : http://www.ehow.com/how_4883556_use-wireless-headphones-tv.html
3
Set the transmitter on top of, or next to, the television. For infrared transmitters, you'll need a direct path between the headphones and the transmitter. Placing the transmitter on or near the TV will allow you to take advantage of the clear path you already have.
4
Plug in the transmitter and turn it on. Charge the headphones if necessary.
5
Turn on the headphones. Adjust the volume and settings and you're ready to watch TV.
Read more : http://www.ehow.com/how_4883556_use-wireless-headphones-tv.html

good luck

their stereo hifi not blu tooth head phones
Amazon com Sennheiser RS 85 On Ear HiFi Stereo Wireless Headphones Silver...

Plug the red and white cables from the transmitter on the headphone set into the red and white slots for audio out on the TV this will supply the sound to the transmitter which in turn send it to the headphones. The transmitter must also be plugged in to the wall outlet for them to work, and batteries in the headphones must be good.

There should be lights on the front of the headset's transmitter box. Are these lit up?
Also, there should be a "palm tree" icon on the left earcup of the headset. When you turn on the headset from the POWER button, the palm tree should flash about once a second. Is it flashing?
If not, you may need to "pair" the headset to the transmitter.

I had the same problem when I plugged it into a new HDTV. The problem was that the sound on the TV was set too low. The transmitter has a feature that automatically turns off when the signal is off or too low. Try turning up the TV volume to a high/higher level and it should solve your problem. Using the headphone jack with the white input allows you to use the headphones while bypassing the TV speakers.

There is a reset button on both the headphone and the transmitter. Try to reset them both before attempting to pair them again. Since the led won't turn on there is a possibility that the battery is not charging. Is the orange light working when the headphones are charging? It should be and then it should turn off when the battery is full.

is this a blue tooth headphone..if yes...if it is, hold down the power button until the led rapidly flashes and then relase the button

Hey, my rca whp141 is incredibly quiet. Go ahead and turn the volume up on the TV.
If that doesn't work make sure

• The headphones and headset are on the same channel (like 1).
  
• the transmitter is on and working (Power: GREEN LIGHT)
• the headset is on and working (GREEN LIGHT)
• the headset is receiving a signal (St: GREEN LIGHT).

Hope this helps.