The DPA PPC4000 is able to test if you have enough phantom power voltage to drive your condenser microphones without changes in their specifications. Furthermore you can use it as a cable tester to e.g. your stage box. The functions are as follows: Green light: Only voltage on pin 3. Core 2 is probably broken. Red light: Only voltage on pin 2. Core 3 is probably broken.
Orange light: OK. Minimum 30 V (unloaded) on both pin 2 and 3. No light: Less than 30 V on both pin 2 and 3. Either no (or not enough) phantom power or a defect cable.
DPA PPC4000 (code 45607)
Phantom Power Checker
£25.45 (inc vat)