It's a Ryzen 1800X. It doesn't have integrated graphics but I thought the X370 motherboards had very basic onboard graphics themselves. Maybe I was wrong. They do have some graphics ports, although maybe those are for future APUs.
Another thing to check is that your cooler is plugged into the main CPU_FAN header (this header tends to need connecting for successful start-up, whether with the CPU cooler or something else) and not a SYS_FAN header.
Further on, if no joy, re-seat the CPU and inspect for any thermal paste stains/hairs/etc on the contact pins and also check for any bent pins. You can do this when/if you try assembling it outside of the case, to rule out a short with the case.