Swift Futura error 24

I have a 5 stop swift Futura. Mg.traction It trips out On error 24 only in the down direction. It will stop immediately and level to closest floor. I replaced the scrs. Didn’t fix it. I’m thinking reg board is the problem. Anybody see this before ? 24 is a drive fault. It indicates a tach fault from reg board it occurs with excessive variance between analog demand velocity and analog tach reference velocity

You’ve done the first things;
Tape guides.
Encoder/tach coupling (motor and encoder). Assuming the encoder is on the motor end shaft.
Tach/encoder wiring in the drive unit tight.

This happens anywhere in the hoistway in the down direction? High speed or roll off to high speed (acceleration profile)?

No other faults whatsoever?
Can you set the RVU to capture the error 24 and then review the recording?

Yes. I did the preliminary checks on guides, coupling etc.. it happens anywhere in the down direction. It happens before it hits high speed. Usually in the first few seconds. There are other faults error 10. Digital tach error. Error 58 fault condition drive Mg or trim / scr

First few seconds huh? That’s quick enough to still be in the mid leveling zone id think.
Do you have job prints? Other than the Regulator Board, maybe look at the modules in the down direction high speed circuit.
Do you have a second unit to swap tach with?
No RVU to trap a fault?
Hopefully you’ve got the set up manual for the regulator.

IIRC, 58, 94 almost always show on any fault condition.