Advent troubleshooting when we power on the unit there is a constant clicking noise and it will not play. it generally will spit back out the dvd

It could be the laser and the disc drive are not working and need to be replaced on your DVD player.

Laser pickup unit fault. The unit alongwith its flat connecting cable should be replaced. Contact any service technician. Electro help

No! take it back to the store, this is a manufacture issue.

Control panel,administrive tools,computer management,device manager scroll to cd/dvd rom drives right click properties then properties again then tick enable cd digital cd audio for this cd rom device or scroll to dvd regions select no _ for your specific area
or
make sure that the dvd burner is getting enough power test all leads that are attached to the dvd burner including electical extensions and make sure they have a secure connection or just replace them there might be bad/faulty or
your drivers may have been corrupted or you might have a virus run your antivrus program
you might have to physically unplug the leads for this cd/dvd burner then plug them back in or
you might have to uninstall then reinstall your DVD/CD or uninstall the driver then reinstall for this device
control panel admistrive tools,computer management,device manager scroll down cd dvd rom drives right click you can you can update driver,roll back driver,or
select properties general troubleshoot, select driver click to reinstall drivers click update driver or uninstall then reinstall
hope this helps

make sure that the dvd burner is getting enough power test all leads that are attached to the dvd burner including electical extensions and make sure they have a secure connection or just replace them there might be bad/faulty
or
you might have to uninstall both the dvd/cd + its drivers then reinstall them actually unplug the cd/dvd from its power cable then restart your computer plug it back in your computer should activate found new hardware or
control panel admistrive tools,computer management,device manager scroll down cd dvd rom drives right click you can you can update driver,roll back driver,or select properties general troubleshoot, select driver click to reinstall drivers click update driver or uninstall then reinstall
hope this helps

check the user manual can be misconfigured or also reviews the mechanism of the lens

On one hand I would say not to be concerned about the clicking since nothing seems to be affected. However, if the noise is loud enough to be a bother, or for your own peace of mind, consider returning it to the retailer for exchange if you still have that option. I've heard clicking sounds from other VCRs because of some of the moving parts and it's been nothing to worry about. But I'm not familiar with the guts of your model, so I can't say it's not a sign of some problem that might get worse over time. It's your call. Not really a "solution" I know, but without opening it up for myself and looking for the source of the noise it's the best I can offer.

defective call customer support or bring it back to were you bought it

Basic DVD, CDrom Troubleshooting
wrong disk ,disk error,
First Clean the lens:
http://www.ehow.com/how_2036275_clean-lens-dvd.html

wont open, wont close, makes clicking/grinding noises etc.
http://www.llamma.com/xbox/Repairs/thompson_dvd_tray.htm

The power supplies in most all the smaller combo units are prone to failure. They feed both the TV and the VCR and are underdesigned as they try to keep the cost of a combo affordable.
I've never had much success solving them - sorry
They always break that last time!