800 lost sound output

I hosted a retro game night last evening and about 1/2 way through the night one of my 800's lost its sound output.  When hooked to a monitor I could not hear anything at all.  Today I hooked it to up via RF and if i turned the TV's volume to the max I could faintly hear some sound.  Faintly beeing the key term.

Any ideas on what i should look at?

Thanks!

Fletch