During boot-up while the Dell screen showa and before the Operating System
begins to load, perss F2 to enter the Set-up (BIOS) where you can set the
boot order.

http://support.dell.com/support/edocs/systems/opsx280/en/ug/advfeat.htm#1052715

    I am afraid that I have already looked in the BIOS. The Boot Sequence in the machine is:

 

1. Onboard or USB Floppy Drive (not present)

2. Onboard or USB CD-ROM Drive (not present)

3. Onboard IDE Hard Drive (not present)

4. Onboard SATA Hard Drive

 

and I have tried with the Drives/Module Bay entry set to On and IDE. Neither of them changed the fact that I cannot boot into the DVD-ROM either through pressing F12 or changing the Boot Sequence.

 

    So why doesn't the BIOS recognize the DVD-ROM in the Module Bay as a bootable device? How can I make do so?

 

    Thank you for your time.

You may want to contact Dell.  I just went through the Documentation for the
SX280 and it is my impression that it cannot boot from the modular bay. Doesn't
seem right.  I got that from the bottom of this page of the manual here under
the heading Boot Sequence .......

http://support.dell.com/support/edocs/systems/opsx280/en/ug/advfeat.htm#1052715

Hello,

 

I had the same problem with two Dell Optiplex SX280 systems I have at my company. Dell sent a technician in to replace the motherboards and it solved the problem.

 

Kevin

    In my case the problem was solved by opening the case, clearing the BIOS (moving one of the jumpers for 1 minute), and starting again. It seems that when I first started the machine it did not have the CD-ROM drive in the module bay, so the BIOS got this fixation that the module bay was empty which could only be ended by forcing it to start all over again with the drive in the bay.

 

    Thank you for all your help.