I open my speaker box and i saw my tweeter is 700watts 4-8Ω and a 10W12ΩJ ceramic cement resistor connected to it, and I saw no crossover.
I would take a closer look at the "10W12ΩJ ceramic cement resistor" to make sure (1) it really is a twelve ohm resistor and (2) that it hasn't been burned out and become an open circuit, especially if it is
in series with the tweeter.
Disconnect the speaker from the amp and make two measurements with your multi-meter set to the ohms function: measure across the tweeter speaker terminals and also measure across the resistor. It will be necessary to disconnect one wire to the woofer speaker before making these measurements since the woofer is in parallel with the tweeter and you don't want that to affect your measurement.
Depending on how the tweeter is made (it
may use a high-resistance ceramic transducer) it may not show any continuity. That doesn't mean it is bad, in which case the resistor may be just a load resistor
in parallel with the tweeter to protect the amp from trying to drive a high-impedance load. However, if the resistor is
in series with the tweeter, then a broken resistance wire under all that ceramic cement will definitely stop the tweeter from working.
With the woofer disconnected for the above test,
and if you measure an open-circuit across the tweeter speaker terminals,
and if the resistor measures twelve ohms, you could test the tweeter for functionality with a nine-volt "transistor radio" battery. Each time you
briefly touch the battery terminals to the speaker terminals you should hear a "click" from the tweeter. If the click occurs, the tweeter could still be bad, but if you do not hear a click the tweeter is definitely bad.
Please tell us if that "10W12ΩJ ceramic cement resistor" is in series or in parallel with the tweeter speaker terminals.