Here's how to bench test and LED bulb swap a Honda / Acura cluster. This method should work on most instrument clusters out there regardless of make or model.

Bulbs used are in the 4000K 6000K (white) range

Correction @ 7:45: You'll need two bulbs if swapping out the A/C button bulbs. Also don't forget to replace the amplifier assembly (blue connector) before reinstalling your cluster.