They look interesting: https://www.soundandvision.com/content/cambridge-soundworks-newton-series-t500-surround-speaker-system

If all that is wrong is an amp, it can probably be replaced but I'd replace the mate in the other speaker as well. As for direct replacement parts, I doubt there are any available unless you can find another old pair to cannibalize.

I have a pair of T500s, bought originally in 2004. These are great speakers, but same issue, the powered amps on both speakers are not working. I've contacted a local tech store that has seen this before and has bypassed the power on the speakers, and set it up so that power to the subs can come from a receiver/amplifier. I'm going to give it a shot, as these are tough speakers to part with, and the Mids and Tweeters still sound great - even w/o the subs. If anyone has other experiences with this, interested in hearing about them, or Aarsenian23 what you did.

I also have t500 with both sub amps bad. I pulled out the amps and now power each sub woth a 250w Hsu sub amp which is externally mounted. Performance is excellent. I was never greatly impressed with the t500 until I hooked up a new Crown 1500 xls.these are incredible sounding with the Crown. I have owned these since 2003 and I can't say enough about the sound since the addition of the 1500 xls. My other speakers are Altec Valencia which I have owned since 1976. The vals were goto now I listen tjo t500 the most. Large rooms 15x28 w 12' high ceilings.

They are worth keeping but need high power amp and speaker mods. I did the following. Purchased two Hsu sub amps new from Parts Express. These are mounted next to my equipment I also removed the sub slave speakers and made reducing rings 12" to 10". I also put a low pass filter in the line 800mghz. Honestly these speakers with the mods and the. CROWN Amp 1500xls are truly incredible.