Mazak QT-20 Mazatrol T-1 Alarm 26 F Servo Amp Z

Hi everyone,

I've got a Mazak QT-20 with a Mazatrol T-1 control. Last year I had the spindle drive die and I replaced it with a brand new one from automation direct. It was tricky but it has worked great ever since. Now I have a new problem. "Alarm #26 F Servo Amp Z". When I turn on the machine the Z-axis moves in the positive direction about 6" suddenly and the machine alarms and e-stops. The Z amplifier is a Mitsubishi Meldas TRA41A and it has a few LEDs that are red that are different from the X amplifier.

Is it possible to retrofit the amplifier like I did with the spindle drive or do I need to find a used replacement? Would it be worth retrofitting the entire control with a new system? The machine is accurate and in good shape otherwise. Would be nice to be able to program with G-code and CAM software but it depends on the cost of the retrofit.

Any ideas are appreciated.

Unfortunately DC servo drives are expensive these days. Maybe have a look at the Centroid AllInOne controller. May be a cheaper and easier option. I'm thinking of one of these for my VQC with M2 control as I have the same drives as you and having different problems

FYI to anyone who's interested. I bought a used amplifier / drive from ebay and made sure all the "setting plugs" were exactly the same as the original. These are the little plastic jumper clips that change settings on the amplifier / drive. Once I connected all the wires the same as before it still gave an alarm when I fired it up. I tried resetting the 30A breaker that's next to it just in case something needed to be reset from having tripped and it worked! The alarm is gone and the machine seems to be working great so far. Haven't tested threading yet but otherwise it's all good.

By the way here's the manual for the Mitsubishi servo amplifier / drive.
https://www.rgbautomatyka.pl/en/p/fi...SHI-MANUAL.pdf