Optiplex 755 cd rom - ASUS Vintage-AH1 Barebone

I used google to search for i/o panel of dell optiplex 755 and got his link http://www.discountelectronics.com/product?gclid=CKTSgfHdscECFeHm7AodD1wA3w&product_id=7297&product_model=18

most likely

Does the dvd work in other players? You might need a video card. or display drivers.

The light on the LCD screen stays yellow?

I would start with puling out the ram chips and see if it works,

If you get some beeps and video works with ram chips out, then its a bad ram chip.

If thats not it.. unplug all cards cd/dvd rom and harddrive to test motherboard and CPU chip. see if you can get video to work with everthing but cpu and power suppy unpuged

make sure that you are closing the CD and also make sure that the cat isnt licking the dogs balls while your doing it.

go to c drive and look for folder called documents and settings inside you will find all the old users from your old windows. in each user file there are more folders one for documents,favorites,music,videos. copy the contents to your new document folder or make a new folder and put all the stuff in it.

dell 755 drivers page

your looking at the wrong firmware

optiplex 755 current bios version: A10 date 6/20/2008

for the CD Drive need to open device manager and check

what brand and model you have for dell used 2 DVD drives
sony and teac

use the correct firmware on drive, if not the drive will be killed.
if unsure open case and look for name/model on sticker of drive

Try the fix listed here - the Fix It image.
http://support.microsoft.com/kb/314060

on the back of each device their should be a jumper on the right side next to where the ribbon cable plugs in. Remove the jumpers and replace them into the slot thats for "Cable Select" Their should be a picture on the top of the device if they aren't labeled. You can also put the jumper for 1 as "Master" and the other as "Slave"

I had similar problem with a Dell Optiplex 760 desktop . I went to BIOS disable external SATA and all additional ports which is not used like parallel and serial ports and it worked. I think its with SATA settings only .