I've added a link to the manual. https://www.zikinf.com/manuels/korg-d1600-manuel-utilisateur-en-38857.pdf
Page 19: Are you able to hear the demo song?
Page 23: Check these settings
Page 38 - 5 : 5. Monitor settings
In order to monitor the audio from the D1600, you will need to connect a set of powered monitor speakers etc. to the [MONITOR OUT L/R] jacks, or connect head-phones to the [PHONES] jack

When you say you can't hear through the monitor, can you explain more?

I plugged the headphones in the front panel phones jack, hooked up my michrophone in the front panel port for the guitar. I pushed a few of the track buttons to red for record. The meter light responds green when I speak, but I hear nothing in the phones. All volume dials for the phones and the track volume dials are also turned up as well as the mater slide, but nothing. I then hooked up a mini amp to the back monitor out input left and right, but still no sound. I downloaded the manual, and printed all of the applicable pages and then some.. ( Quite complicated ) I haven't had time to really get into a lot of it, I did read something about the proper track assignment or something like that ) The whole manual is about 160 pages. Pretty overwhelming. I just wanted to achieve basic operation, and then get into more later. I hope this can help. Thankyou Danny

Hi Danny, welcome to RO.

Is the Solo / Monitor Button blinking?

I will get back to you. Thankyou . Is it supposed to be?

No. If it's blinking, some other channel may be overriding the monitor outputs to eavesdrop on that one input (which may be a channel you have nothing plugged in to).

It would also be useful if you could tell us (or show us) what you see in the display when you press that Solo / Monitor button.