Please help my 804s tweeters are not working

Yep, tweeters are usually more vulnerable than other speaker drivers. Woofers are usually blown when speaker is overpowered and played loud or destroyed by analogue LF rumble.
Crossover will less-likely be affected.

out of curiosity did you try moving your center to a front position to verify that you are not seeing some sort of signal or crossover issue. seems odd to me that both would go, assume at the same time. I'm in noob territory on this one so take that for what its worth.

simple - call your dealer