Computer wont play a video i recored with my camera on my sd card

If you copy the data from the SD card to your computer using a USB card reader, that might possibly do the trick.

what is the model of the cam?

some cams only do video
depends what its saving the file as
may be your software that wont play the audio but plays the video ok
check the codec used to save the audio

Are you sure you have an SD card (2GB or smaller)? The 508 won't work with higher-capacity SDHC cards.

First, make sure you have it on CARD (and not DISK), and on the "playback" (and not record) mode. Next, does the camera play back other video clips normally, but just not a specific clip ?
Does the selected video clip frame (index) shown on the LCD screen have a picture ? If not, i.e. it is blank (dark), then it is likely that no video was recorded (i.e. just the audio) when you were shooting that video clip.
If there is a picture (of the video clip frame index on the LCD screen) and only audio is playing, try downloading the clip (from the SD card) to your computer, or simply try to play the video on the SD card (inserted directly into your SD card reader on your computer, or via a USB SD card reader) and see if the video clip will play normally on your computer.

Probably because the tv doesn't have the correct circuitry to play videos. If you have a VHS recorder connected to the tv, you could download the video to a tape and play it that way. I have a Dish Network HD DVR. It has a usb connector allowing me to download to the DVR and play slide shows and videos.

take of the memorycard from camera and just put your sd-card to the memorycard slot and open it from my computer. and if you dont have one just connect camera to computer with cable

Did you change the file name on the original video? Are you able to put the video back onto the camera? If you changed the file name, you can't put it back onto the camera. It also needs to be in AVI format which is the video format that the camera records in.

Hope this helps!

dvd player on computer must handle dvd-ram standard

I'm no expert, but I don't think you can do that with just the video camera alone. First you'd have to pass your video onto a computer using dv motion studio and then you can put that output file onto a sd card. I don't think it would be possible to play that video off the card on the camera. Hope that helps