Question computer not booting with ebay radeon 6800

[SnappyCat360]

i took out my old gtx 1660 and put in a radoeon 6800. now, its not turning on and when i hold down the power button the light blinks and it doesnt turn off. i put the 1660 back in and doesnt work. treid booting off of another drive didnt work

 

[logainofhades]

Need full system specs in order to even begin to help you. This includes make/model of your power supply.