Probably the ribbon cable from video to DMD is seated incorrectly, off a pin.
TOM makes a slight high pitched metallic sound at startup from my experience, but you should still hear a bong from the speakers, or an error chime. And again, make sure there is sound during game play.
If the price on the machine is right, all this stuff can be corrected for additional cost.
Unless you are sure what you are doing, buying a game that can't be put into test mode can be dodgy.