Background hissing noise from wireless headphones

[sspj9]

I accidentally dropped my Sony MDR-RF855RK wireless headphones and as i plugged them in they worked fine as before though there is this annoying loud interference which is increased as volume from headphones is increased, obviously. Before  I dropped it this was barely noticeable though now its really loud. Think its from the receiver circuitry. Any ideas were the fault might be?

[n45048]

Those particular headphones I believe use an analog FM signal for transmission. The drop might have been enough to knock a RX tuning pot slightly out of whack.

Don't turn it on, take it apart, and try to adjust the tuning (at the right tongue angle of course!)

[sspj9]

There was nothing to adjust on the headphones receiver. I tried checking out the transmitter. It had 3 components to be adjusted though 2 of them were for balancing and the other was for loudness, nothing to do with the hissing. :/

[Psi]

yep, they will have been knocked off frequency.
A tune should fix it, use a plastic screwdriver or tuning stick.

If it doesn't have any tune-able components in the RF section then look for air core inductors, maybe the impact has bent the coil slightly.
Be very careful and adjust in really fine amounts while listening to it, if you throw it far out of tune you may not be able to find it again.

[sunnyhighway]

Try change the radio frequency with the CHANNEL selector on the transmitter, then change the radio frequency to that of the transmitter with the TUNING switch on the headphones.

[n45048]

There was nothing to adjust on the headphones receiver. I tried checking out the transmitter. It had 3 components to be adjusted though 2 of them were for balancing and the other was for loudness, nothing to do with the hissing. :/

Just to confirm, you actually pulled it apart? It probably won't have fine tuning capabilities that are accessible to the user.

[sspj9]

Yeah, there were 4 air-core inductors in the rf reciever. Bending them made it worse lol. I just kept it as it was..