Listing the specs would go a long way with finding an answer to your question. You did not give an details about your GPU aka Graphics card, power supply, hard drive, RAM, CPU, etc. It's possible that one of the other parts are bad. We don't know if you think the GPU is integrated into the motherboard or something of that sort.
The onboard graphics port at the back of the motherboard will only work if you have a Ryzen 3 2200g, Ryzen 3 3200g, Ryzen 5 2400g, Ryzen 5 3200g, Athlon 200GE. Processors like the Ryzen 5 2600 or 3600x do not have Integrated Graphics built into the chip.