Sounds like a bad laser -- not unheard of in a system/drive this old.  Clean the lens of the laser -- if that doesn't solve the issue, replace the drive.

Will it read a pressed disc (software install disc or music CD)?

It doesn't. I tried putting a disk in and it lights up and spins but then stops. Also. fyi I tried removing and reseating the drive, still no change.

M4800 uses a slot loading drive so it's not easy to access for cleaning the laser lens comparing to a tray loading drive.  You may want to check in Disk Management to see any error with drive letter assignment.

Drive letter Ok. I read somewhere that if bios and device manager are showing the dvd drive then it is a windows problem?

I see that you have another post with Wi-Fi problem.  From the information gathered so far, both issues are more likely with software than with hardware.  Considering the troubleshooting time with posting questions and answers, it could take hours or even days.  Before any spending to replace hardware, I suggest to get a small SSD and swapping out your current drive(s).  Performing a clean install of Windows 10 just for testing.  The whole process may take up to an hour but it may resolve both issues (optical and Wi-Fi) at the same time.  If it doesn't fix the issues, simply put the system back the way it was.  

If you decide to take that route and needing help with the process information, just ask.

How do I do a clean install of win 10. I don't have any disk.

If you meant spare SSD disk for test installation, can't help you with that.  If you meant optical disk for installation tool, you won't need one.  A USB drive can be used, see the tutorial link below.  Either performing test or repair/replace the optical drive.

To start the creation tool process, click here to download the tool.  You will need a USB drive of at least 8gb.  Double click on downloaded file and follow the process to create an installation USB drive.

Review this old tutorial for information and to get an idea of the process, making the work easier.

Remember the suggestion to use spare drive so it doesn't affect your current system.

Chino de Oro - Thank you again for your help. I created the USB OS. I noticed that it seems to be for std Win 10. I have Win10 Pro. Does this matter?

If you follow the tutorial and making the USB to use on other machine, the OS is for all versions.

Stay with your objective.  This is suppose to be a quick test to rule out hardware issue.  So, don't spend hours or days with it.  And do not install over your current drives or setup until your new installation can resolve all issues.  That is when you have to make a plan to update/upgrade your machine to fix problem and gaining better performance. 

Do not forget to install Intel chipset driver from Dell.

Do not forget to run Windows updates and installing all drivers updates from Optional Updates.