Turn on the meter without hooking up to the Sovereign. This meter is a multi meter to measure voltage and without it hooked up to the Sovereign is should read 000, this will tell you the meter is working, if it shows 1 then that is the overload on most meter. which is the voltage to high for what the meter is set at. I would also check the battery of the meter as it has a battery either in it or on the back of the meter. with it not hooked up to the Sovereign and you get 1 when you turn on the Sovereign you have a bad meter. Make sure the wires are not connected to the meter, if it shows 000 the meter is working , if it shows 000 with the wires connected then hook it up to the GT and if it shows 1 then there is a short in the wiring where it ic connected to the GT. It is a process of elimination until you find where the problem is.
The meter is a voltage meter and it is spliced between the control box and the coil so it is taking the sample of the voltage to let you know my the numbers on the meter what the tone is. Without it some of the tones are too close to tell the difference in and you can read the numbers to get a better ID.
When you get it figured out so it reads other then 1 (thats overload on a digital meter) it should read 1.79-1.80 on a clad quarter or dime, I beleive the nickle will be 1.44 or so in band 2 on the GT as it is close to what my SunRay meter is. if it is not when the meter has to be re-calibrated which depends on the date the meter was made as there is a difference on how you do this.
One piece of advice if new to the Sovereign is dont give up and learn what you can from experience as it will be well worth it in the end, just ask anyone that has kept a Sovereign with the 180 meter.
Good luck and if you got a problem with the meter feel free to ask as we will get it figured out.
Rick