A stuck volume button on a Toshiba television can be a straightforward problem or a symptom of a more complex issue. Televisions vary by style and features, but small things such as the volume button work the same regardless of the model of the TV you own. Troubleshooting will give you an idea of the cause of the button malfunction and how to fix it.
When troubleshooting any electronic device, it makes sense to start with the simplest solution first. In the case of a stuck volume button, a space between the button and the casing can trap dirt and limit the movement of the up or down volume controls. Cleaning around the button with a damp cloth is a first step; if necessary, you can unplug the TV and clear the debris with a toothpick or pin.
A volume problem doesn't always indicate a malfunction with the television. Some issues stem from the remote control or its sensor -- a small, red or tinted piece of plastic, like a reflector, on the front of the TV. If the sensor is dirty, adjusting the volume via the remote may not work. You can test this theory by using the volume buttons on the TV itself; if they work, you know the remote or the sensor is the problem. If wiping the sensor with a clean cloth doesn't prove to be the solution, you may need to change the batteries or use a replacement remote control that's compatible with your Toshiba TV model.
Resetting the TV
Once you rule out dirt as the culprit, the possible cause of a stuck volume button becomes more complex. Toshiba televisions, like most modern electronic devices, use circuit boards to manage their processes and power supply. A stuck volume may indicate a malfunction with a board or another internal component of the unit. Resetting a television returns the TV's configuration to its factory settings, and thus may correct whatever is preventing the volume from changing. To reset the TV, you need to unplug it and leave it unplugged for a while; the exact time necessary to reset the unit will depend on the model, but an hour should work regardless of which Toshiba you own.
If the volume button is still not working despite your troubleshooting efforts, the next step will be to take your Toshiba TV to a service center. At this point, the problem is beyond basic home repair and requires professional service, such as replacing one of the circuit boards or the button connection. If the television is under warranty, Toshiba's website provides instructions on service requests (link in Resources). The company will request the TV's serial number; for most models, you'll find that number on the back of the unit.