I've bought 2 Dreamcast official light guns to play House of the Dead 2. One works flawlessly and the other has definitely had a hard life. I've disassembled it, cleaned it up, replaced the broken tactile switch behind the trigger and got it working perfectly in game.
Only problem now is it won't use either the vibration packs or VMUs. VMUs beep so receive power but don't seem to get data. Nothing displays on screen, be it the VMU logo or the game logo. All work fine on the good light gun and all hand controllers. I would prefer to fix it rather than send it back only for them to consign it to landfill. What could be wrong and what could be a potential fix?
I was thinking possibly dirty contacts on the controller considering how utterly filthy it was. What would be the best way to clean them?