Some weeks ago I serviced the above mentioned machine, it used to show 3 alarms on the screen:
a) 201 - Breaker trip
b) 221 - Turret clamp sensor malfunction
c) 33 - Emergency stop
The machine had been just sitting there for more than a year when I was called in, actually I was the third tech in the lineup. Originally the spindle drive of this machine was sent to Mitsubishi for a mayor repair, but when it returned fixed the machine wouldn't work.
I found out that alarms a & b were caused due to the +24 volts power supply being zeroed because of a short circuit between the footswitch wiring and ground.
So I focused on the 3rd one and after some reading I figured out this E-stop alarm was caused by the machine's drives system, it was not the general E-stop machine alarm wich has another code (number) and is caused by the lack of continuity in the E-stop string.
The #33 alarm was present because somebody, at some moment, took off a piece named Terminator (or final connector) from the spindle drive and forgot to put it back, so we ordered a new piece with MEAU, rechecked all the rotary switches in the drives configuration and everything got back on track.
I decided to upload a video showing that service, hoping it will be used as reference/help by somebody out there, there are some pictures here also.
"http://www.youtube.com/watch?v=vmsnCstUe0U"]YouTube- SOLVED... Mazak QTN10/QT20