partial display after new HDD install?

Recently i bought an xbox one original console only with the intention of repairing it. I bought a power supply then tested the console and it wouldn’t power on. So i opened it up and saw the front ribbon cable was disconnected. after plugging it in power came on but i received another error, so i opened it back up to find that it doesn’t have an HDD, i formatted a new hdd and used software to set it up with OSU1 on my pc. after installing HDD xbox starts and shows startup graphic in low resolution, then the screen shows solid black with a thin blue line on top and bottom. If i hold the X button on the controller it brings up the power option for xbox and controller but nothing else. holding pair button and eject does not bring up troubleshooting menu so i cant use OSU from flash drive . Any suggestion as to what the problem could be?