Take out the rpm meter from the unit and exam the back carefully.
You will see a coil of copper thin wires. Look carefully to see if one of the wires that go to the post got cut or loose.
This is what happened to my unit and I took it to a speedometer repair shop and had him resolder it for me. I didn't trust my soldering skills and didn't have all the right equipment to do such a delicate solder. It cost me $25.00
if you Over tighten the screws on the back of the cluster board ,it will break the thin copper wires coiled in the Meter, I learned that the hardway of another car. but if you have never touched or Altered the mileage on you NSX ( Illegal ) then its probably the sensor in the engine not the cluster. my 2 cents
nope, no GPS installed, but changed to JVC double DIN DVD player. Now, i found that the cluster is giving me other problems. EPS follows after the RPM and SPEEDO went up and down when engine starts. After that, i will have to take of the clock jumper to reset the fault. I cant do this everytime. Its really embarrass when you do it in public!