Hey, I've got a KLH sw-12 powered subwoofer. Few years old. It doesn't work. Any ideas on how to test some things to check and see if anything is blown? I'm not an expert, to say the least, on electronics like this.

This will show you how to check the capacitors.

FIRST: short the terminals to ensure it is not charged.
Many of the digital meters today also have a capacitance check setting, simply use that setting. It not only checks for faults, but also will give you a reading of the capacitance value itself.
For most non-electrolytic capacitors a quick check (definately bad vs. maybe good) can be done with an analog VOM. Use the highest resistance scale to measure across the terminals. When first connected there should be a short needle jump that slowly drops back to infinity. Reverse the leads and do it again, should have the same effect. Any resistance highter than infinity indicates a shorted capacitor. Lack of needle jump may indicate an open capacitor (or one of very little capacitance).
Electrolytics can also be checked with a VOM, but polarity must be observed, and the drop back to infinity may take a very long time.
Alternatively, for electrolytics and larger capacitors is to charge them with a low voltage source (e.g. 9V battery) and measure with multimeter to see if they hold the charge. Hope this helps
This will show you how to check the capacitors. FIRST: short the terminals to ensure it is not charged. Many of the digital meters today also have a capacitance check setting, simply use that setting. It not only checks for faults, but also will give you a reading of the capacitance value itself. For most non-electrolytic capacitors a quick check (definately bad vs. maybe good) can be done with an analog VOM. Use the highest resistance scale to measure across the terminals. When first connected there should be a short needle jump that slowly drops back to infinity. Reverse the leads and do it again, should have the same effect. Any resistance highter than infinity indicates a shorted capacitor. Lack of needle jump may indicate an open capacitor (or one of very little capacitance). Electrolytics can also be checked with a VOM, but polarity must be observed, and the drop back to infinity may take a very long time. Alternatively, for electrolytics and larger capacitors is to charge them with a low voltage source (e.g. 9V battery) and measure with multimeter to see if they hold the charge. Hope this helps