California Brownouts and equipment

A few weeks ago, while my wife was watching a video, a brownout occurred. Not knowing to shut everything off, she simply went to bed. Sometime in the middle of the night everything came back on. Now the VCR won't record. I have all my audio and video equipment connected to a Audio Research Ref One preamp which is connected to a Plinius SA100 MKIII amp. It's all plugged into a Richard Grey's Power Company 400s. My question is can a brownout cause damage to my equipment? If so, how severe? Not knowing when a brownout may occurr, are there any suggestions?