Do you have the latest BIOS installed on your system ? The last BIOS version is 0801, dated 2019/05/15. Is your motherboard's onboard graphics working fine, without the GPU ? Also, please try to reset/clear all the CMOS/BIOS settings to default as well, if need be.
Even though the VS650 isn't the very best of power supplies, it should at least give the signal/display, imo. Which Monitor do you have ? Maybe try using the Display port/DL-DVID of the RX 570, assuming yoru monitor supports it.