If the BIOS does not show the first drive.

by R. Proffitt Moderator - 1/31/12 9:41 AM

In Reply to: primary hd not recognized by gdtrfb

Then it's likely the connector on the main board has failed. As you are a computer repair tech you know to pull the board and see if you can touch up the solder work and re-try one last time to avoid replacing the mainboard.
Bob