Many Dell computers have onboard diagnostics software. If a user presses the F12 key upon powering on the Dell computer, the computer will go into the diagnostics menu. If you are not familiar with this diagnostics software, This program checks for any errors within the computer’s hardware. In this blog post, I will talk about a computer that keeps rebooting into the Dell diagnostics software automatically. I will also explain what was causing this issue.
A Dell Latitude 7420 that I was working on reboots automatically into the onboard diagnostics software. Although software may be a possible cause of this issue, the real issue is hardware related. A ribbon cable that connects the touch pad to the motherboard was causing the problem. The ribbon cable had a slight bend in its contacts causing a short. Straightening out this bent contact resolved the issue.
Here is the touch pad connector
Here is the connector on the motherboard for the touch pad
And here is the ribbon cable that had a bent contact causing a short, which caused the computer to loop into the diagnostics software
