Can't read internal SSD
Please help me with this issue, With Internal Drive in, the machine seems to be having issues booting and/or recognizing the drive, I only hear the startup sound and that’s all. When the internal drive is out that’s when it’s will show the question mark(?) which I know it means it can’t find the startup drive, Booting from external works fine only when the internal drive is disconnected, with the internal drive connected it can’t even boot or see the external drive.
What might be causing this issue to happen and how to sort it out.
Thank you in advanced..