Broken Nakamichi CA-7A phono


Hi,

I have just received my Nakamichi CA-7A which I bought from an ebay seller for $900. I was super excited to use it to replace my CA-5, which works great with my Rega TT (Ania MC cartridge) though it has a few issues with balance control.

While the new CA-7 works great with my CD player, Aux (Chromecast Audio), it makes a broken noise (not sure how to describe it, please see this video) as soon as I switch it to Phono input. 

https://www.dropbox.com/s/beafocypf4bawvb/VID_20200216_120837.mp4?dl=0

This is the case whether or not my turntable is attached to the phono input.

I have double checked by connecting my TT to existing my CA-5 and connecting it to CA-7 Aux1/Aux2 (of course very low gain). And, i verified that input on the rear panel is correctly configured.

I have reached out to the seller to see if he can help me out. Can anyone of help me figure out what could be going on here?

Thanks
objectivecpp
Post removed 
Get your 900 bucks back and buy something new for the same amount that you spent on that 30+ year old preamp. This would fit the bill! 
https://www.audioadvisor.com/prodinfo.asp?number=PAC200PRE
Please tell me you fixed that Nak ca-7a? The first plain old ca-7 was very nice. But I kept hearing about the phono stage in the ca-7Aii, which I now have. And they were correct! The entire pre-amp is better. I tryed twice on eBay with bo the being sold as mint. For $800-950 for each. But both had issues. I ended up paying the actual going rate for one in mint cond. "$1650" . But well worth the price. If you ever get the Chance, take the top off the ca-7, or any Nak unit of that era and you Will see why they are so special! As far as buying a new pre for $900 that sounds simply "As good"? That is NEVER GOING TO HAPPEN! That Nak when you adjust? About $4500 in today's money! The Nak though old? Is several levels above that "Parasound" which was offered.... And remember, the ca-7 and pa-7 models were Nelson Pass designs. With his "Stasis" Architecture!
Awesome gear still!