Displays message unknown disc no matter what disc I put in...

It would more likely be the types of discs used. They are either of a region code not compatible with the player, contain foreign/unknown data, or they are unsupported formats. For example, if the player supports DVD-R playback, and you put a DVD-RW in, the player will generate 'wrong disc' message if the player cannot recognise the disc or the contents on it.

The disc formats/types that can be played should be outlined either on the unit itself or in the instruction manual (if you still have it). If the player shows that message even with genuine shop-bought DVDs then there is a defect within the unit, workshop attention may be required to fix it, but it could be costly.

'WRONG DISC' usually means the disc inserted is of a different region code to the player, or the wrong format (DVD-RW instead of DVD-R as exampled above). Try using different discs before going any further.

either the disc motor is not running up the disc speed fast enough,or the laser is burnt out.run it with the cover off and look at the disc speed.it should be about 500rpm

my lg dvd model dr389 displays PRO1 please solve my problem

hello,
you can try this
This hack enables VCD playback
Power on the player with no disk in the drive
Press "PAUSE" on the remote
Enter "1472" on the remote
Press the UP arrow three times
Press "PROGRAM", "5", "PROGRAM", "5" (the characters 04 EE should now be displayed)
Press "ENTER" (the display should flash briefly)
Press "RETURN"
Power the player off and then back on

Thank you

I have had the same problem a few times. All I do is eject and re-insert the disk until it recognises it, this seemed to work for me

when disk is in dvd message reads bad disk.

machine might only take - dvd or + dvd only some take both types will show on front of machine just a thought

you can try to use a cd lens cleaner CD. Put the lens cleaner in slot 1 and load disk 1 the cleaner shouls be dropped in place and begin to clean the cdrom lens.

OKAY GUYS TRY USING THIS VERY COMPATIBLE MEDIA

(MEMOREX BRAND DVD-R) THIS WILL SOLVE A LOT OF YOUR PROBLEMS