Updated problems:

Converter makes whistling, high pitched whine, or buzzing noises. the converter either stops working and the noise happens, or the converter makes the noise when off/standby or the noise worsens with use. converter may be hot to touch.

SOLUTION

Back in the early days of Home Theatre, this sort of thing happened often with low quality or inexpensive VCRs, LaserDisc Players, or other gadgets. it's usually the power supply transformer having an 'arc' or literal spark jumping a gap of winding inside. it will cause heat to build up and of course make the component warmer than normal to the touch. it's the result of bad or poor quality components in cheaper electronics. it's a fire hazard as well. in some cases the component may immediately stop working or power off and the sound changes to a high pitched squeal or whistle. that is after the transformer shorts the windings that were arcing and most likely it causes the component to smoke and even go boom (pop! no more component)

If your converter is doing such things, it's HIGHLY RECOMMENDED that the converter is taken back to the retailer (during the 30-day return/exchange period, remember, if you used a coupon you're either limited to exchange for same item only or you may lose the ability to return at all so you're stuck buying a new box) as this condition is a power supply issue that can cause a fire or electric shock.