Advise need for mistibishi toyo denki invertor

Dear Friends,
I really need your help to make a desicion. I have 1F5 Mistibishi 1999
model. Recently i have problem in my Invertor TOYO DENKI VF 61 S-3022 model.
it shows a error OV . I have reset the invertor and it was working fine. But for the last 20 days. We could not run the machine due the OV error.we could not reset it because once we reset it , again the same error comes as soon we start to run the machine. All the parameter settings are correct. I had send the invertor for service. The service person is saying the Module is fine and the no problem in the invertor. The power is correct and the input is 205 volt. If we decrese the input also the same error comes. kndly advice me how to proceed.

thanks
Ganesh