by stuck and not moving - i assume the needle remains in the same position when the amp is off as well as on - if this is the case, the meter itself will need to be checked. At times, these VUs may get stuck/ceased/jammed and can be easily fixed by opening them up and simply freeing the needle assembly. In some cases, i have noticed that the stuck needle is due to physical damage, something breaking or bending. If this is the case, then one can attempt to repair or simply replace.
If the needle returns to null position when off and is stationary at the position shown in the photo when turned on, then you will have to troubleshoot the circuitry which is wired to the meter (the meter coils and not the bulb/LED). If the meter itself is mechanically and electrically ok, then you have the working channel for comparing voltages to.
Additional info: The process for diagnosing issues with electronics is similar to a doctor's diagnostic methods when we report sickness. More complete information on the symptoms, or operating conditions when the issue was first noticed, a more detailed description of the issue, etc would be very helpful for the exact 'prescription of treatment' which in this case, is the fix
