kymjets wrote:
I have a problem with 2 of my DVD players. They read CDs fine but when
a DVD is inserted, the DVD player doesn't even register that it has a
disc in the machine. Can anyone help me fix this problem?


(This assumes the discs aren't just dirty or damaged)

Sure. Replace the laser pickups. The parts may well cost more than the whole
players.
Some require fairly extensive adjustments be done after replacement. This
requires a service manual and a decent oscilloscope, and appropriate
training to use them.

The blessing and the curse is that the price of new (el cheapo) players has
dropped so far that replacement is often FAR cheaper than repair.
Unfortunately the quality of the new units being sold are often sub-par.
Pioneer still seems to make a decent player.

Mark Z.