Ideally with garage compressor, but a tyre inflator pump might work provided it doesn't leak back through the pump.
Make whatever adapter you need to 6mm airline. Also put an 8mm loop on the two dryer ports.
Leak checks
Now connect the 6mm line to each port & pressurise it to about 60psi.
Get your soapy water spray ready. For each port check below, spray the corresponding valve body & check exhaust port for leaks.
Starting with the tank port, this will prove if NRV-1 and the Inlet valve are holding pressure.
Next connect each corner port in turn. This will prove the corresponding corner valve holds pressure
Electrical Checks
On the main connector from ECU to the driver pack, Connect 12V to pins 12 & 13. Ground to pins 10 & 11
Now connect 12V to pins 1 to 6 in turn to check the solenoids operate.
While the solenoids are engaged, wriggle the wires entering the driver pack. This will check for intermittent driver pack wiring.
Now connect the airline to compressor port, and apply 12V to the diaphragm valve. Make sure no air is escaping the exhaust port.
It sounds complicated, but in reality takes less time than installing the block in the car. Also this way you can check the two valves underneath the block easily.
In my case I used a small bench tank plus pressure gauges to check the block holds pressure over a few days !!
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