I was wondering if a mixer that is not in good condition would have an affect on the sound quality. I bought my mixer used and it's not really in great condition. I get a bad sound through it and my microphones are decent. I heard the same class of microphones through a new mixer and it sounded ten times clearer. Is it possible that the bad sound i am hearing is due to my damaged mixer?

there are more variables at work than just whether the mixer's kaputt:
1. the monitors and amplifier attached to the mixer's output will colour the sound to a degree.
2. the preamplifiers in your mixer will also be colouring the sound before it even hits the eq section of the channel strip (you can take an insert out if you want to hear the raw signal at this stage). the harder you amplify the signal through the preamps, the more noise and colouration will affect the signal.

you might consider trying a second pair of monitors or a second amplifier for the monitors to ascertain whether your monitors are problematic. then you might consider using some discrete mic preamps to boost the microphone signal before it gets to the preamp in the channel strip.

that said, a broken mixer will affect the signal. like much in life, this seems self-evident. to me at least.