KEB F5 = DC Bus voltage coming, Control card OK, but Display Power Not found, how do solve this problem.

I may miss the point here. If the question is how to clear the error, page 57, item 4.7 Error Messages, of the KEB instruction manual may be of use. https://www.manualslib.com/manual/1293218/Keb-Combivert-F5.html?page=55#manual

Here is information about the error code:

KEB Error "E. OP"
ERROR overpotential (voltage)
1 Voltage in the DC-link cicuit is too high.
Occurs if the DC-link circuit voltage exceeds the permisible value.
Causes:
- poor controller adjustment (overshooting)
- input voltage too high
- interference voltages at the input
- deceleration ramp to short
- braking resistor defective or too small

Given the very technical nature of the KEB, I lean toward referring to the manufacturer's support. There are quite a number of KEB YouTube videos and a number of supporting documentations available on the web. Perhaps the following will be of use if not an entire misdirection: https://www.kebamerica.com/elevator-support/

https://www.kebamerica.com/products/f5-inverter/

This may be due to the inverter waiting for an ST signal via buss communications.

What is the part # of the unit in question?

The inverter is recognizing that terminal 16 is going active but still waiting for another command to enable the inverter.

E.uPh due to the ripple detection of the DC bus. This is typically caused by a missing phase on the input side of the inverter.

Measure your mains voltage L1-L2, L2-L3, L1-L3 and L1-ground, L2-ground, L3-ground to verify that your supply voltage is balanced and withing the rated specifications.

If the applied voltage is good then there is a problem with the input stage or the DC bus and the unit will need to be repaired or replaced.

If using bus communications (Can, ProFi, Mod, ext), there may be a communications command (Software signal) that is not being provided. Hardware and software enable signal required to obtain LS.

Possible that the terminal on the control card is bad due to miss connection or signals outside of the rated value.

There is a problem with the channel 1 feedback loop.

Possible causes:
Loose connection at encoder or feedback card.
Defective feedback cable.
Defective encoder.
Defective feedback card.
Defective control card.
Defective inverter.

Measure the applied AC voltage phase to phase and phase to ground to verify that it is present and correct.

If you can connect to the inverter with the COMBIVIS software, look in the ru parameters to see what the inverter is actually measuring the DC bus voltage at.

Ac mains voltage x 1.414 = @ DC bus voltage.

Do you mean no_Pu error?

Reason for error = 24Vdc is being applied to the control card but the mains voltage is not being applied to the power stage.

E.puch means that at power up the control card did recognized the power stage as different than last time it powered up.

This is normal when the control card is changed. If the control card has not been changed, there is a problem between the power stage and the control card.

Initialize the value at sy.03 to reset the error.

Most likely when the DC bus capacitors and input rectifier were damaged, it also damaged the circuit board.

Wiser to replace inverter or send it in to a KEB facitlity to be repaired.