My PSW 125 Subwoofer Has the "Heart Beat" sound problem

Hi,
I have a Polk Audio PSW 125 Subwoofer, serial #AM122513192. I purchased this speaker, two TSi300's and oneCS10. I bought them in Jan 2014. I have enjoyed them a lot. Now the Subwoofer has the heart beat sound. I found a website http://mrfxr.com/polk-subwoofer/ that claims there are 2 capacitors on the amplifier board that go bad. He shows a picture of the amplifier board with the 2 capacitors circled. Is this a good fix for the problem? If not is there a way I could get a replacement board from Polk Audio like some of the other people on this thread have recently done? I am from Washington State USA. Thanks. Rob .