No error beeps but the indicator light is white (so graphics).
I do have a spare GPU, I'll have to try that in the morning.
Another option would be to try the onboard IGP.
Just to cover the bases, do you have another monitor and/or cable you could try?
Main System: i7-8700K, ASUS ROG STRIX Z370-E, 16 GB DDR4 3200 RAM, MSI GTX 1080 TI, 1 TB WD_Black SN750, Corsair 550D
HTPC: I5-4460, ASUS H97M-E, 8 GB RAM, GTX 970, CRUCIAL 256GB MX100, SILVERSTONE GD09B