Hi Cypher and welcome to the forums.
First, sounds like it may be a power issue with the pulsing. If it is the packs, seems like you are on the right track with a capacitor issue.
Second, I would give service a call. They would have all the diagrams and be able to help you troubleshoot. Just make sure you have the pack/s in front of you when you call them. Also, the ones that are only a few weeks old should still be under warranty, so they can issue an R/A for service.
However, since the ages range from years to weeks, I would assume its more likely a power issue within the building. So my question to you then is how are they receiving power? Each one have its own 15/20 amp circuit or doubling it. Pulsing lights is generally a sign of voltage drop. Any sound gear on the same outlets/break box? When the amps hit big notes, general low-end, they draw more wattage which can cause this effect. I have seen it become so bad before, I have witnessed the effect in LEDs as well.