[blakester]

I'm trying to get a 4th axis indexer working and I am getting the following alarms. 403 is the 1st alarm, 703 is the 2nd alarm, and I have the "HCAL" alarm light on the velocity unit. Any ideas would be greatly apppreciated.

[Al_The_Man]

Presumably no one has changed the parameters? if not you should check the motor, preferable off load, if the fault persists check the motor itself, all AC voltage input to the drive o/l's fusing etc.
I assume this is DC motors so check the brushes and blow the carbon out, it is preferable to remove it for inspection if the brushes are low.
Could also be a drive failure, if you have others on the machine of the same size, you could interchange them for a test.
Al.

[blakester]

Al,

The control is a 6MB. The servo is a seiries 5. I Have set all of the parameters myself according to the maintenance manual, but I will double check everything. I can try swapping out the velocity unit, but can a H003 amp work for series 5 servo like the H002. I also noticed that when the control tries to power up the servo "jolts" and then the alarm appears. I turn the servo by hand and it feels a little gummy inside from coolant perhaps, so that my might be the problem as well.

[Al_The_Man]

Disconnect the armature leads, it will probabally not fault at that point, that may confirm a motor problem, it could be the tach, if one is fitted, or loss of encoder feedback.
Al.

[not an expert]

HCAL on a DC M series (Yellow cap motor) is one of three things typically. Motor, motor power cable or the drive itself. If the motor/cable is shorted to ground and you install another drive to the shorted combo you could potentially damage the drive you install. Be careful with the almighty HCAL it will dip into your checkbook.

If you have disconnected the motor leads and still have the alarm then it is inside the drive. You can pull of the top pcb and ohm out the transistor modules and look for a dead short.

[blakester]

I have uplugged the cable servo leads (4 pin cannon plug), even the motor leads on terminals 5 & 7 on the amp and still get the 403 alarm, so it must be in the drive itself, I am looking at the amp now with the top board removed. Where are the transistors to ohm out and check for a short?

[not an expert]

As long as the HCA light is still lit on the pcb you can check the drive. If the top board is an A20B-0009-0320 then it should have 4 transistor modules (T-mods) located behind the board mounted horizontally. There should be five screws in each T-mod with wires attached to them. If you look close on the T-mods they should be labeled left to right C-B-CE-B-E. Collector, base emitter (Each T-mod has two transistors inside of it). Check for a short between C-B, C-E, B-E. Forward and reverse polarity (Meter leads one way meter leads the other way). If you see anything around 5 ohms you have found the problem. That T-mod will need to be replaced along with the top pcb.

On a side note if the pcb is a A20B-0008-0361 (I think) Then that drive has SCR's located inside the drive and that is a whole different style of trouble shooting. Good luck

[blakester]

The board I have is a A20B-0009-0320. I had a spare board and swapped it out and still get the 403 alarm, but not HCAL light. All of the jumpers on the boards are set identical according to the maint. manual. I will check the transitors you described next. I was also wondering if the H003 amp would work to power a series 5 servo because I have a spare I Could swap out. I have the H002 that the book recomends for the series 5.

[not an expert]

At this time I can't tell you to safely swap the drives. BUT if you do find a T-mod that is shorted and they are the same part number then you can put that in place of the shorted module. Only bad news is it has been my experience if I had ever ran across a drive with the HCAL and just put a top board on, there is a chance that board is now damaged even if it's not given you an alarm.

[blakester]

Thanks for all your help. What causes the HCAL alarm exactly? Does a short in the cable between the drive and servo cause it?, or do they just go bad, or both. I will test the t-mod's in the morning and test the top boards as well with one of the x,y, or z axis drives the see if they are still ok....I will Keep you posted...Thanks again!

[not an expert]

T-mods usually fail with normal wear and tear. There are other factors that can speed up that process. Shorted motor, cable, coolant... rats chewing on cable's (don't laugh too hard I've seen it!) I do need to make a correction though. I think earlier I said mounted horizontally, I meant vertical along the top of the drive (it's getting late but I'll check this thread tomorrow morning to see how you're doing) Take your time and you'll figure it out.

[not an expert]

Had to post it here your private message box was full:

FINALLY some progress!
The 703 could be generated from the motor itself. I'm not sure if your motor has a pulse coder or just the tach. If it has the pulse coder it should have two white wires not really in the pulse coder harness. All the other wires will be colored and the two white wires will actually go into the motor. Those go to the physical overheat. When I have to change out pulse coders on the motor I have to cut those two wires and then solder them back into the pulse coder harness. It's kinda hard to describe but easy to to see what I'm talking about once you pull off the yellow cap. I know you've swapped motors but it's still worth a look. The overheat has to be tripped for a reason. I'm trying to remember if the drive has an overheat in it but it's been swapped also. I'm going back to the jumpers. If the motor doesn't have an overheat then the overheat should be jumpered out on the board?

[blakester]

I checked the overheat circuit. On pins 8 & 9 on plug CHX2 of the pulse coder board I have a closed circuit, which is what it says it needs to be according to the diagram. I have had the servo apart and cleaned it and the brushes looked great. What do you show for jumpers on board A20B-0007-0090 revision F? I changed them per what another guy told me, which was different than the book, and that got all of the drives to power up and just left me with the one alarm.....the 703 that has always been there.

[mithunrams]

.

[ckirchen]

Old thread, but it helped me out immensely...that's what I love about CNC Zone!!!

I had 401 alarms popping up every now and then, but they would always clear by cycling the power, so they weren't a big deal. Today, I had a 401 that was persistant.

I opened the cabinet and saw that on drive had the HCAL light was on. A quick search of "Fanuc HCAL" and I found this thread. I pulled the axis board and started to check the T-Mod just as not_an_expert describes. I got about halfway though when I noticed that one of the T-Mod screws was loose. I tightened it and without checking the rest of the pins, I put the board back on and powered on the machine. 401 error was gone.

Just to be safe, I checked all of the T-Mod screws and did a full continuity check; all was OK.

I'm pretty sure that the loose screw combined with machine vibrations was causing intermittent errors. Without this thread, I would have never thought to look under the axis board. Thanks again!

Chris Kirchen

[andy.f]

Hi guys,

Great forum this is!
Same problem. After checking T-mods, motor wiring etc. I tried swapping top pcb's between Z and X. It caused a breaker to pop and I could not press STAND BY button to see if HCAL stayed with axis or PCB. I took out both PCB's and desoldered the 1 x 1" black component with part# A76L-0300-0035/T, swapped them and soldered them on small wires to avoid another de-solder procedure if needed. I managed to rip out a few vias and traces in the process, but it is easy to diode check to see where the parts 5 legs should go and fix it with some wire. After replacing the pcb's the problem is gone, so likely a bad solder by Fanuc or a previous user.

Thanks to all previous posters. After 2 years of head ache the HCAL mystery is solved!

Andy