Sierra boots from external drive but not from internal one (same disk)

[Loomart]

Hi guys,

I've installed Sierra to my drive Kingston hyper x 120G ssd connected externally and it booted ok.
Then i connected it directly to the mainboard and now it does not boot.
It shows the apple logo and approximatelly at the middle loading bar it stops and shows the forbidden sign.
Do you have any idea about what's going on ?
Thanks in advance

 

[Bob_the_Tomato]

Welcome @Loomart to these forums.
1st) You need to fill in the details of your build in your profile (per forum rules) or we’d be just guessing all day.

2) When you boot from USB you use different part of the BIOS to access the disk. Booting internally uses different hardware. I’d check your BIOS settings. Where did you get the info to make your build? Follow their settings.