My portable stero works when plugged into the wall, and until yesterday it worked running off batteries. But now when I put batteries in it it doesnt work, but it still works when plugged in.

Want to help you but can you provide some imfo like year model etc of your car .all cars runs if you have both gas and spark

put a battery in it or replace the battery already there.

Sounds like the connections may be oxidised. With a long, sharp knife scratch at the metal contacts at each end of the battery compartment until they are shiny,and make sure your batteries have good life in them. If that does not work there may be a broken wire connection inside, or, less likely, a short circuit has occurred that is draining the batteries (I doubt that though)

Unplug,replug tv it back an hour later let the tv reset itself back to factory setting.Should power up and work now.If tv run on a Litium battery.Check the battery,might needed to be changing.

it depends on what you are using to charge it with.
if you are charging it on the computer make sure that the plug that goes into the computer is in the right location and the plug that goes into your ipod is not in backwards.
if you are using a stero and it is not charging try to push the ipod in all the way and if that doesn't work then use something to push your iPod forward. or just see if your stero is working correctly. if not try a wall charger or a car charger. those usually ALWAYS work.

I had the same problem until I noticed I was running Vista SP1. Search and download Vista SP2 and you will be good to go

Well you can try this if you still got the zen, press the reste button, dont hold just press it then hold down the power button and it will start up but mine just kept on going black fter a while so i had to put it into recovery mode by doing the following.
Hold down play untill the end
Press the reset button
Hold down the power button
Makes sure you releas the play button last
after that do Reload Firmware i think
then it will delete the firmware make sure you have this downloaded on your computer
http://support.creative.com/downloads/download.aspx?nDownloadId=10889
its the newest firmware
when you downloaded this plug in your zen into the computer and it should turn on your zen and then say Firmware problem and if it doesnt just put it into recovery mode then plug it in.
Then make sure all application are turned off like Mozzila or the Internet Explorer, then just double click on the firmware and it should fix

Yes the battery could very much be dead since the PSP hasnt been used in quite a while. I would go to a store such as walmart or target and buy a new battery. Charge this one and try it in the PSP. If this doesnt work, return the battery for a refund and send the PSP in for repair to SONY.

First try disconnecting ALL power to the laptop - not just at switching off at the wall but pull the plug and remove the battery as well. leave it for 30 seconds or so and put it all back and try again.

If no luck then press F8 on boot until the boot options screen appears and select 'Last Known Configuration'

If no luck then is this XP or Vista?

I have the same unit, and had the same problem numerous times. I finally removed the battery and sprayed CRC electronic cleaner over the battery terminals as well as the units terminals. Put the battery back in hooked up the charger and it went green. It is playing as I write this.