Schematics for the bike are hard to find. Schematics for the cluster are next to impossible unless you draw it yourself.
Instrument clusters have become mini modules or computers and as such, you must look at them the same way. Do you have the schematic for the bike and if so, can you share it on here? Have you made sure that you have all power and ground wires connected to your power supply as well as the switched ignition supply?
Have you checked all the solder joints to the main connector and then followed the teaces for power and ground?
Check all solder joints thst you can as clusters are known for loose joints.
Make sure that the battery is fully charged and that it passes a load test.
Check the red/blue wire (I think) that feeds the cluster. Do this by checking for battery voltage and load the wire so that the integrity of the wire is checked as well.
Check all this and get back to us. I will check to see if I have any notes on this cluster..
Checked my notes...Often times the main harness will be chaffed and will wear the wiring down to a few strands. You will see full voltage or light up a test light, but not power up the cluster. Hence what I said above about loading the wire to test the integrity.