Alarm 20 NMI emergency stop and alarm 204 spindle controller malfunction

[bdrotaru]

Hi
I have a 1986 QT20N with Mazatrol T2 got from a auction with a spindle problem.
On gear 1 machine get to 900 rpm but brake to 0 rpm is taking over 6 seconds. Acceleration to rpm's is ok.
On gear 2 machine get to 2200 rpm but deceleration to 0 rpm is taking over 10 second. Even so! When machine is braking in gear 2 never manage to stop. I get Alarm 20 NMI emergency stop and Alarm 204 Spindle controller malfunction. Alarms are disappearing after shutdown an main braker in OFF position for couple seconds.
I don't think it's normally for the machine to take so long to stop the spindle. I've seen some videos on YouTube and there was a much faster deceleration.
It is reasonable to suspect that Alarms 20 and 204 have same cause?
Anybody faced this issue?

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[bdrotaru]

Are there any brake resistors in this machine? Maybe are burned or disconnected. I don't know where to look.

Thanks

[bdrotaru]

I attached a video with this behavior. Any advice please?

[navinbhas]

Please share the alarm occuring on the spindle drive unit as well. also mention the drive unit model

[bdrotaru]

Hi. Thanks for reply. It is a Fanuc a20b-1000-0693 controller. And I get Alarm no 2.

Trimis de pe al meu SM-J530F folosind Tapatalk

[navinbhas]

Sorry I have no idea about Fanuc controller with Mitsubishi drives