My frigidaire window AC is not cooling anymore

Does it get cold? You can try cleaning the fins-both inside and outside, with windex. Smoling & cooking will create a sticky deposit that will make dist that gets through the filter stick and it won't cool properly.
If it doesn.t get cold any more, try replacing the starting capacitor. About $5. If that doesn't take care of it, just replace the unit. They are cheap enough these days, that you can replace a unit with a more energy efficient unit for the same cost or less as a repair would cost.