Double DIN Eonon GA8166 No Audio

[littlex5]

I bought a double DIN Eonon GA8166 and paid a local audio shop to install it on my 2005 E53 4.4. It was working fine for a while but one day it stopped producing audio. Everything works, just no sound. Long story short, the audio shop and Eonon have been pointing fingers at each other with no resolution. The last idea Eonon has is for me to check whether there's 12V going into the DSP. First of all, I need to know if I have a DSP. Someone told me I do have it based on the attached photo. Is there an easy way to determine if the DSP/amp is getting power? When I press the voice command button on my steering wheel, I do get speech response from the car's audio. Does that proof that my DSP/amp is working properly?

Here's Eonon's response:
"Does your car have DSP system and AMP? If it has AMP, please kindly check if the AMP control cable has stable 12V?"

Here's website for the Eonon head unit:
https://www.eonon.com/Android-Car-GP...o-Display.html