Haas Alarm 161 & 991

I receive two alarms at the end of milling: Alarms 161-164 AXIS DRIVE FAULT and Alarm 991 AMPLIFIER OVER TEMPERATURE

The temperature of the shop is 60 degrees, and I was running my first program of the day (so machine had been off). So I can't imagine the amplifier was over temperature. I could touch all 3 amplifiers with my hand and none felt warm.

So Haas states that if these two alarms are triggered, to check the cooling fan (Servo Amplifier - How it Works and Troubleshooting Guide | Customer Resource Center). The fan appears to be running fine; moving a great volume of air. But what confused me is that the Haas troubleshooting guide recommended checking the voltage to the fan:


Haas says that if the cable has the correct voltage, then the fan is defective. The cable showed to supply 119v. Can a fan be defective even though it seems to be running fine? Has anyone experienced this?

Thanks.

I can't help directly, but "amusingly" my '98 VF-2 has given me those alarms (at least, I think they're the same, I need to check again) when my Z-axis decided to crap itself a couple months ago.

I did note a classic "burning electronics" smell at the time, so have not tried to restart the machine since then. Will deal with it soon, but fortunately my newer machine is still working fine (knock wood).

You'll need to dig deeper. Which axis faulted? Was it at startup or while running?

If I try to fix my older machine I'll update this thread if I find any obvious culprits. Please do the same as you try to get yours fixed.

Milland said:

I can't help directly, but "amusingly" my '98 VF-2 has given me those alarms (at least, I think they're the same, I need to check again) when my Z-axis decided to crap itself a couple months ago.

I did note a classic "burning electronics" smell at the time, so have not tried to restart the machine since then. Will deal with it soon, but fortunately my newer machine is still working fine (knock wood).

You'll need to dig deeper. Which axis faulted? Was it at startup or while running?

If I try to fix my older machine I'll update this thread if I find any obvious culprits. Please do the same as you try to get yours fixed.

Click to expand...

It's saying the X axis amplifier is the culprit. The lights indeed go out on the amplifier when the alarm is triggered.

What's weird is the alarms seem to trigger at the end of a program. I ran three different parts and at the end of the program, when the vise rolls forward and the spindle raises, the alarms trigger right before all of that. So the spindle is kind of stuck down and I have to reset the machine to move the spindle up and get my part out. But again, the alarms seem to trigger at that last stage. I know Fusion 360 just performed an update. I don't know if code could have something to do with it. It just seems weird I can mill an entire part using XYZ for 30 minutes and then alarms trigger at the end of the programs. I can reset the machine and hang jog all axis so I can't say something is physically obstructing the X axis from moving.

OK, that's weird. My machine is truly DOA, there's no coaxing it to do a run. And I can say pretty catagorically that it's unlikely a command from your G-code could bring these alarms if the machine is otherwise sound (which it isn't).

If you have a thermal imager (not just an IR thermometer) you could try checking the boards in the cabinet for unexpected heat zones, that's part of my plan when I dare to restart the machine.

If you're really bold you can swap Y and X drives and try running a modified program to use the revised available travel, but be damn careful to not wreck the boards/modules/cables, etc. I presume this is an older machine? What year/model?

Milland said:

OK, that's weird. My machine is truly DOA, there's no coaxing it to do a run. And I can say pretty catagorically that it's unlikely a command from your G-code could bring these alarms if the machine is otherwise sound (which it isn't).

If you have a thermal imager (not just an IR thermometer) you could try checking the boards in the cabinet for unexpected heat zones, that's part of my plan when I dare to restart the machine.

If you're really bold you can swap Y and X drives and try running a modified program to use the revised available travel, but be damn careful to not wreck the boards/modules/cables, etc. I presume this is an older machine? What year/model?

Click to expand...

It's a 2010 Office Mill 2A

tayamo1 said:

It's a 2010 Office Mill 2A

Click to expand...

Hmm, not had any time on an Office Mill. Those are teeny (ISO 20 taper?), they may use drives unique to that machine as I'd imagine there's no need for anything as large as the VF series servos.

At least your machine is new enough you should have access to a complete range of replacement parts.

Milland said:

Hmm, not had any time on an Office Mill. Those are teeny (ISO 20 taper?), they may use drives unique to that machine as I'd imagine there's no need for anything as large as the VF series servos.

At least your machine is new enough you should have access to a complete range of replacement parts.

Click to expand...

Correct ISO 20 taper. They are babies but fun.

What's weird is I can mill for 20 mins no problem so it doesn't seem to be an issue with the motor or amplifier.

Well, I'm back to trying to use a thermal imager, ideally one with good resolution. Take some pictures while the machine is cold of the electronic enclosure, then run it 'til you get the alarms, then take fresh pictures to see if any components are obviously hotter than others of similar purpose.

I'd also try elevating the questions from your local HFO to CA, see if they can help.

If anyone is interested, Haas's technicians suggested to swap the x and y amplifiers. The alarm then triggered on the Y axis so they suggested the x amplifier is bad. I bought new amplifier and all seems to be working. Thanks to those who chimed in.