If only one crossover died, and it's usually from over-voltage/clipping, you can use the other to copy it. If you were really cranking the schnikies out of them, it's possible that your capacitors have been badly stressed. If the labels are still intact, replacements are easily available from Parts Express, Madisound and other suppliers. If you can solder, you can repair a crossover. Drivers are another issue. If you don't hear anything from the tweeter, use a digital multi-meter to check it's resistance. If you see a number that's much higher than about 3 ohms (for a 4 Ohm speaker) or around 6 Ohms (for an 8 Ohm speaker), it may not be good and you'll need to replace it, if it's definitely out of spec.