"Goes up" means that you see an indication on the TV screen that the volume is being adjusted?
Make sure the the source isn't the problem. Try a different source. If you use a set top box that could have the volume turned down or set incorrectly in a menu.
Check that the TV speakers are turned on in the TV menu.
If the TV has a headphone jack then try inserting and removing headphones a few times. There is a mechanical cutoff in the headphone jack itself.