Video Playback Issue

Is the lens cover opening ?

Press PLAY (right-pointing triangle) to enter the PLAY menu, then select "COPY."

Were they shot with the TZ3 or in another camera or from a computer?

You need a program on your computer to play it. Quicktime is a good choice...it's a free download if you don't have it.

check to see if there is a certain setting it has to be on find the video that you recorded on you camera and then click ok or whatever button you have to press to play it.

Hi,

The picture that I posted shows a TZ3 mode dial. I added a blue arrow to point out an icon on the mode dial.
----------------------------------------------------------------------------------
1. Turn the mode dial on the camera so this icon is selected.
2. Switch on the camera.
3. Aim the camera at your subject, press the shutter button halfway to focus, then press it fully to begin the video. (Just as you would take a picture.)
4. To stop taking video, press the shutter button fully again.
-----------------------------------------------------------------------------------

~When a video starts being taken, its current length will appear on the camera's LCD screen.
~Videos take up more space on the memory card than do pictures.
~If an SD memory card becomes full while recording, then the video will stop automatically.
~Videos can be played back on the camera's "PLAYBACK" mode. They can also be viewed on a TV or downloaded to a computer.

iPhoto is for still images only....! You should use iMovieHD to edit video (on Mac)

I don't have a solution to the first part of your dilemma (why it won't playback) but I do have a solution for deleting the file.  On your camera are "hidden" file folders.  When you connect your camera to your computer, you probably only see two folders (that's all I see for my DMC-LZ8).  But there are more, and your undeletable picture/video is in one of these folders.  Find the folder and you'll find the file.  Delete it from your camera using the computer to do the command.  Problem solved.  Okay, so how do you find the hidden folders?  I have a Mac, so my process was this:  1) Connect camera to computer; 2) Select/open camera icon (looks like "volume disk"); 3) From top Finder bar, select File then Find;  4) Select the camera volume to limit your search to the camera (not HD or other external hard drives you may have connected to your computer); 5) Select "Kind" and in the next dropdown button "Folders".  Voila.  Happy searching.  My hidden "undeletable" video files were in a folder called "100_PANA".  I selected them then moved them to the Trash.  Be sure to eject your camera properly (don't just turn it off or disconnect it).
Good luck.  I hope this helps.
PS - My theory is that this occurred after an upload to my computer got unexpectedly disconnected before everything finished loading or else the camera got disconnected from the computer incorrectly even if the upload had already finished (see above comment to eject camera properly).  In either case, the blank/black screen, unviewable but "there" on the camera taking up memory photos/videos problem happened to me, too.  The above actions resolved it for me.

Panasonic use .MOV Apple Quick Time format for it movie clips. Win Media won't play them. Does your computer prompt you for what program to use to play unknown file?

Down Apple Quck Time free program,

Read your DVD Player Software Instructions/Capabilities.