RPM gauge not working

[raficanio]

Hello guys !!

I would love to get your opinion regarding the problem I have since I bought my CBF 600 of 2008 on second hand.
When I turn on the contact the rpm needle does the 'checking', but then when starting the engine the needle no longer moves.

Is it possible that the rpm cable that reaches the engine has any problem? or is it really the rpm that is faulty/broken?

Thank you very much in advance for your comments !!

Best regards,
Rafael