Speedmaster 74/4 1993 error

Hello, I have the following error on a 1993 Speedmaster 74/4. Now the machine does not run. What could it be?
Help me
Thanks

 

It can be variant key problem please check your variant key sir

 

THANK YOU, I don't know how to check the fault. The command displays remain OFF. Also in the 2 steps in the photo the LEDs are off. Is this correct?

 

In the second picture the led of the two ntk board must not be off , try to check connexion , supply voltage or repair the board if it s defective .
Good luck

 

Thanks for your reply. It could be a power supply problem. I think it is 24V, I thought some fuse. But I can't figure out where the board's power supply is. I don't have any wiring diagram.

 

You can test with the same down ntk in the cabinet to know if it s board issue but check first if there is a short circuit

 

good morning it seems that ntk goes to 0V input. I checked the GRM24 board: Input 26V x 3 phases, output 0V (0.013V)

 

You can test with the same down ntk in the cabinet to know if it s board issue but check first if there is a break circuit

 

You can repair the grm board

 

Ok Thanks. There is a three-phase diode bridge rectifier. Input is 24 V AC. According to the calculations it should output 32 V DC, isn't it too high to power the NTK board? Does NTK have a 30DC to 24VDC stabilizer? Thanks

 

I will send you the power on the grm board , it s not the same

 

ok thanks