If your MSY2 does not work as expected please check these items:
When the external power supply is connected to MSY2 (still without Midi connection) the Clock LED has to turn on permanently and the Start/Stop LED has to remain off. If this does not happen the power supply is defective or unsuitable: if both LEDs remain dark the polarity of the power supply is reverse or the power supply is defective. Even if the Clock LED starts flashing (without Midi connection) the power supply is unsuitable (e.g. a power supply with AC output or a faulty DC power supply)
If everything is OK connect the Midi output of your Midi transmitter to the Midi input of the MSY2 with a suitable Midi cable.
Pay attention that the MSY2 responds only to the Midi realtime messages Clock, Start and Stop. MSY2 cannot be controlled by other Midi messages like Midi timecode or Midi note on/off.
If your MSY2 does not respond please double check if your Midi transmitter actually outputs Midi Clock, Start and Stop. For some units or programs this function has to be activated explicitly.
The start/stop LED has to turn on when a Midi Start message is sent, it has to turn off when the Midi Stop is received.
The Clock LED of the MSY2 has to blink with the Midi Clock tempo (according to the setting of the clock dividing factor with the DIP switches). If the Clock LED does not blink no Midi Clock is sent by your Midi transmitter ! MSY2 will work only together with Midi outputs that correspond exactly to the Midi standard established by the Midi-Association. Particularly pin #2 of the Midi output socket has to be connected to GND. Otherwise MSY2 will not work. If the Midi Out socket of your device does not comply exactly with the Midi standard MSY2 will not work !
We recommend the usage of a power supply rather than powering the unit via Midi (for units manufactured from summer 2014 powering via Midi is no longer possible). Pay attention that the correct power supply is used: 7-15 V DC unstabilized or stabilized voltage, as well as a minimum current of 100 mA. The polarity of the low voltage plug connected to the MSY2 must be pin = +7...12V and ring = GND (see sketch on the MSY2 housing).
Pay attention that all five pins of the cable are connected if the SYNC connection is used (at least the pins 1, 2 and 3). For Midi cables that may be not the case.
If the LEDs of the MSY2 display clock and start/stop as it should but the device connected to the clock and/or start/stop outputs does not respond, it might be a problem with the voltage levels. The levels of the clock and start/stop outputs are 5V (0/+5V). If the device connected to MSY2 requires other voltage levels the MSY2 is not suitable.