All the S meters that are used in CB’s that I ran across over the years are measuring volts, not current. Volt meters don’t have a parallel shunt like a current meter that would somewhat protect the coil from too much voltage being applied. I would never place a any battery directly across a meter unless you first know the type of meter you’re dealing with. A full scale reading on most of these volt meters used in CB's is around 50 microvolt or .00005 volt. I don’t think any of them contain any internal series resistor /shunt either. That’s all done externally when needed. 1.5 volts will slam the needle and possibly damage the movement and coil. For a quick test, some people suggest placing a 47K resistor in series with a 1.5 battery. Others talk of using a 50k pot in series, and then they slowly reduce the resistance till the needle starts to move. Ooops! Forgot which end of the pot had the maximum resistance, slam / pop, another meter bites the dust. I simply test them with my cheap $5 digital multimeter from Harbor Freight. I usually start out at 200K ohms for safety. Most of these CB meters will indicate about quarter movement at 20K and a little over half way at 2K.
Pivot freeze is the main problem by far and easiest to fix, but like Kopcicle stated, the moving coil releasing itself from the tab is also common. I have successfully (brag) soldered a few of those coil springs back into place as a challenge. Credits go to my +8 power glasses, fine tip soldering iron, clamps and several makeshift jigs taped together out of whatever is in the junk pile. Oh I forgot, practice holding your breath like you getting an X ray. Fail or not, I’ll keep trying to fix these difficult problems again when the time arises. I can’t help myself….
