How to fix a frequency shifted audio part of an RF signal?

[qbgjkls]

I tried to connect an old Japanese (NTSC, System M) video gaming system (an original Famicom, HVC-001) to a rather modern multisystem LCD TV-set (Sharp LC-43CFE5222E using LH28F160S3T chip). The TV tuner is capable of tuning to the signal, but I can't get both clear image and sound at the same time.

As can be seen in this video, the image is clear at 91.750 MHz. However, on this frequency the sound is not. If I use the fine tune control to adjust the frequency a bit higher to 92.125 MHz, the sound becomes clear, but image becomes distorted.

The game system has a channel switch with two options: CH1 and CH2. This problem happens on both of them, only the absolute MHz values are different.

Since I know only little about electronics, I would appreciate help finding the source of the problem. Is the game system broken? Is the TV tuner of low quality? Even if so, would it be possible to build a device that would shift the audio part of the signal this tiny bit?

[FAMICOM_87]

try this
http://www.famicomworld.com/forum/index.php?topic=12027.0