LG LH-D6230 plays cd's(to a degree) but not dvds or pic cds?

I have just been given a faulty unit and it was doing the same as yours. Cleaning the lens in mine was not a quick job because the drive unit had a metal cover, so I had to:

Disconnect unit from power
Unscrew and remove case top
Disconnect all cables from the DVD drive unit
Unscrew and lift out drive unit
Remove screws from cover of drive unit
Unlatch the cover
Clean the lens (Carefully!) by 'brushing' it extremely gently with the corner of a lint-free cloth (no rubbing) - this is not really a good way of cleaning a DVD/CD lens due to the way the lens assembly is contructed - I consider this a 'last resort' method.
Reassembling the whole lot

The unit is working fine now!

Neil Kay
December 2007