On Wed, 30 Dec 2009 15:17:11 -0800, (Dave Platt)
wrote:

Upon trying to use my Panasonic portable DVD player (DVD-LS90)
I noticed the remote control has no effect on the unit. The battery
is good and makes good contact.

Is there a easy way to determine if the problem is the remote
transmitter or the receiver in the DVD player?

Many camcorders, and digital cameras can "see" near-infrared light to
some extent. Point the remote at your camera, look at the camera's
monitor screen, press a button on the remote, and see if you see
"light" from the IR emitter diode.

If you do, the remote is at least transmitting... although it might be
transmitting the wrong unit-code (if it's switch-selectable between
units) or might be emitting gibberish (if it's been dropped, and the
internal crystal oscillator has been damaged enough to shift its
operating frequency too far).

If you don't see "light" when you push a button on the remote (and if
you do, when you try the same test on a couple of known-good remotes
of some sort) then there's a fair chance that your remote is frotzed.

I just tried this. The remote is emitting. It is the DVD specific
remote control. Correct me if I'm wrong, but the chances are
that the receiver is the problem.