Air Conditioning - Central A/C Water Leak

I have a 5 year old Carrier system and it has leaked the last 2 years and was "fixed" by a service provider. It leaked again - it appears that the drain pipe leaving the coils is somewhat dry, the drip pan is mostly dry, the drain pipe leaving the drip pan is clear but the unit itself is filled with water as it the large pan underneath the unit (it's filled with an inch of water).

Is something clogged, if so where should I check?

OK - i fiqured out the problem... I have a crack drip pan near the drain pipe. Can this be fixed (sealed) or should I simply get a new one.

If the latter, is it easy to replace?

Dont the over flow pan under the unit have its own drain ??? It should have . To the outside of the home and over a window,door or walkway. I dont know if you can put a new pan under that unit. Might try and seal it with some epoxy sticks or a Marine-Tex Epoxy putty.