Replaced the inverter, now makes noise.

Basically, the backlight started to fail so I replaced the inverter, and this inverter now makes an annoying noise. How can I solve this? Is the inverter bad? Can it be the inverter cable?

Thanks

More details:

The backlight works fine now. When the brightness is at max or minimum it does not make the noise. Depending on the level of brightness the pitch of the sound changes, and for some angles of the screen the noise is considerably louder.