Stereo lights and sound cutting in/out

I've read hundreds of posts to try and identify what I'm experiencing to no avail, so thought I might try my luck with a new post...

I have a 2006 Prius with Nav/JBL audio. For nearly 8 months, my stereo has been cutting in/out intermittently. When it cuts out, it has the following effects: lights on the stereo itself dim almost entirely, and: AM - completely silent; FM - I hear fuzz; CD - music plays, but volume is significantly cut and sound is heavily distorted (particularly bass frequencies); AUX - acts the same as CD.

I've confirmed that the fuses are fine. Assuming it will fix my problem, I would like to replace the stereo with a new double-din deck, but I am not sure how to tell whether I am dealing with a stereo deck issue or a amplifier issue. Given the dimming of the lights, my guess is that it is the stereo itself and not the amp - I would prefer not to have to mess with replacing the amp.

Has anyone experienced anything similar? Any thoughts as to whether this sounds like a stereo deck problem vs an amplifier issue?

Thanks in advance for any feedback.

 

That's possible - I did have my original OEM stereo replaced by the dealer and I think they use refurbished parts for the replacement. It's possible that they installed it incorrectly, but I have had them confirm that all connections are firm. And the intermittent way it cuts in and out - it seems random, but it has gotten worse over time. Also cannot explain why only quiet static comes from AM/FM, but distorted music comes from CD/Aux.