Kaos, i gotta tell ya buddy, you'll get more and better responses to your questions if you help eliminate possibilities by doing some due diligence and posting all that you've tried.
use your statement as an example.
you key your mic and you get 1 watt out.
OK, well, here is a list of questions that you should answer yourself, and post in your thread before you make a bunch of people guess.
1. what was the output before?
2. mobile or base?
3. antenna checked and known good?
4. did it happen instantly, or change as you were talking on the radio?
5. what work has been done to the radio?
6. did the modulated power go down also? how much?
7. did you already check the driver and final?
as you can see, each one of these questions could lead to a different answer, so the more details you can give, the better help you can get.
you might try posting again with a detailed description of your station, and the situation that caused you to notice the problem.
you will find that if you answer all the easy questions that you can, people here will be more likely to offer up suggestions on the harder questions.
good luck!
LC