First off, replace your dampers if they're old. They're $8-20 parts (USD) so there's no reason to cheap out.
Second, try a really long period custody wash, say 99 minutes, to try to loosen up any clogged nozzles in your black head. That head looks terrible.
Third, calibrate the machine, and then recalibrate on a regular basis. I do both a print.adjust and a bi-directional adjust once a week to keep it nailed in. I also put it into maintenance mode and do the fine adjustments once every six months or so, but that's pretty advanced.
Fourth, if your calibrations seem to drift really fast, check your encoder strip. It might just need a cleaning, but it's also a relatively easy/cheap part to replace if it's beat up.
Fifth, get a proper cleaning schedule set up and stick to it diligently. You should be cleaning gently around the heads with a proper cleaning swab and cleaning fluid on a regular basis--we do it daily first thing in the morning, alternating who does it as that eliminates personal bias in cleaning procedure.
If none of that helps, and you're sure it's not media comp, check your environmental variables. You want to be around 72F ambient and ~50% humidity for optimum printing. There's plenty of fudge factor in those numbers but it's something to shoot for.
