Fanuc 6T - 401 SERVO alarm

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02-08-2009, 07:35 AM
Roger Z

Fanuc 6T - 401 SERVO alarm

Tsugami Mercury lathe with Fanuc 6T. Got this old beast cheap and repaired the mechanical problems. Am learning Fanuc programming. After several weeks of programming, got the lathe to make parts and was in the middle of editing a line and suddenly got a "401 SERVO" alarm. Found "HCAL" LED illuminated (high current alarm) on the X-axis (left side) velocity control PCB #A20B-0009-0320/07C. After much mechanical checking, found nothing. Swapped the 2 velocity PCBs and the "HCAL" stayed with the PCB. I have been trying to troubleshoot to find the component(s) responsible, but need a schematic to go farther. The ICs Q3, Q4, Q5, Q6 and some of the resistors in that area have fantastically different voltages between the two PCBs. Again, swapped the PCBs and the voltages stay with the PCB. I believe the problem is on the PCB, not in the axis drive. Any ideas? or can anybody supply me a schematic diagram? I tried first with GE Fanuc and had NOOOOO luck. Also had no luck trying to connect the 6T to a PC so I didn't have to stand at the control, but no luck. If this problem can be solved, I will be back to trying to connect to RS-232. Thanks for any help!
02-08-2009, 12:01 PM
Dan Fritz

The first thing I would check is the input voltage. Sounds like your 3-phase voltage is too high for your transformer settings.

Look for a big 3-phase transformer in the cabinet (probably below your servos). This transformer can be set with jumpers so that the servos get the right voltage regardless of the shop's line voltage. Instructions for setting these jumpers are in the fanuc Maintenance manual. You should be able to adjust the transformer to accept any line voltage between 190 and 550 vac.

Also, there is a smaller single-phase transformer near the CNCs power supply. There are multiple taps on the input side, and the wire should be attached to the right tap for your line voltage.

This issue comes up whenever a machine is moved. The shop where it was before might have had a different line voltage.
02-08-2009, 06:22 PM
GPena

If you swaped the boards and the problem goes with the board (to the Z axis) then the poblem is in the board, getting the diagrams won't be an easy task. As my experience there is a square black box in the board wth a yellow label on the top (1"x1" apro.), this is an opamp from Fanuc, the problem could be there, to isolate the problem you can change that part from one board to the other and test, if you find that this is bad then you can buy it from Fanuc.

Good luck.

Greg.
02-08-2009, 11:21 PM
Roger Z

Dan thanks for your quick response!! This lathe was moved from a shop nearby, with the same power. BUT, I would like to check the voltages as you recommend, because the transformer(s) may be set wrong. We have a TOOLING MANUAL, a PROGRAMMING MANUAL and an OPERATOR'S MANUAL, but no MAINTENANCE MANUAL. Where can I get this? Do you know where I can get a schematic diagram for the velocity board? or do you know the real ID number of those ICs that I mentioned? If I can get a data sheet for them, that would also help. I checked all discreet components and found nothing wrong. I expected to find a shorted diode or semiconductor or a bad capacitor, but all looks well. This leaves me with the mysterious "packaged" components.
02-08-2009, 11:30 PM
Roger Z

Greg thanks for your reply. I will investigate those black cubes. I really need a roadmap for this circuit board, because it is double sided foil and parts are painted and the whole board is coated with some yellowish film. The foils are almost impossible to follow. I am a skilled electronic technician but am not able to go any farther with my troubleshooting. I need some real service information. Where is it hidden? GE Fanuc doesnt even answer their phone! I was just playing with the phone menu system and waiting an hour listening to music every time I called. I have spent probably 15 hours over a month trying to get a person. It is shameful!
04-14-2009, 06:22 PM
hiiesalu

401 ERROR HCAL LED LIT REPAIR

I FIXED MY IKEGAI AX25 FANUC 6T AS SUGGESTED 401 SERVO AND HCAL LED LIT.
1.I SWAPED BOARDS A20B-0009-0320 AND THE PROBLEM FOLLWED THE BOARD, "MAKE SURE"!!! THE PLASTIC JUMPERS LOWER LEFT HAND OF BOARD
ARE SET FOR X AND Z ON MY MACHINE THEY ARE SET DIFFERENT. REMOVE TWO CONNECTORS AND RELEASE TABS THAT HOLD BOARD, BEND TABS JUST ENOUGH TO REALEASE TO FAR AND THEY WILL BREAK.

2. IF PROBLEM FOLLOWS THE BOARD THEN REMOVE BOARDS AND REMOVE 1" SQUARE ISOLATION AMP AT6L-0300-00317 USING A SOLDER SUCKER AND SWAP THESE "BE CARFULL TO REMOVE PART GET ALL THE SOLDER OUT" . IF PROBLEM FOLLOWS THEN REPLACE WITH FANUC PART I PAID $168.00

3. AFTER I REPLACED THE PART AND POWERED UP I WENT TO DIGOS # 800 AND 801 AND ADJUSTED BLUE TRIM POT MARKED "OFFSET" (LOWER LEFT)
AND SET 800 AND 801 TO ZERO BY TURNING KNOB RIGHT OR LEFT

Summary the AT6L-0300-00317 is a common part failure the proudcure too about an hour and save me the cost of a complete board and or service call
04-17-2009, 04:41 AM
Roger Z

Thanks for your reply "hiiesalu". I found a used PCB (printed circuit board) for $250 and just swapped it and the lathe is up and running again. I had located the approximate area of problem, and there were four integrated circuits, which had Fanuc part numbers on them. I was not able to get any schematic diagram or any information from GE-Fanuc. There are several money hungry repair services available, but they can go suck someone else's blood. I will NEVER have anything to do with Fanuc in the future, thanks to the way they operate. I still have the bad PCB and will attempt to repair it if I can get some more information. Then I will have a spare. I am wondering where you got the black cube thing from? Did you order from Fanuc or some other place? They told me that they will not sell to me because I am not one of their authorized repair services. This experience opened my eyes to future machine purchases. If I can not get service information with the purchase, I will buy another brand. Thanks to all for your comments!
04-17-2009, 03:41 PM
hiiesalu

Fanuc parts direct

We have in stock. The price each is $168.00.

Thank you for the inquiry - ordering contact information shown below.

Best regards

Luis M.

GE Fanuc Terms and Conditions of Sale apply to all orders and
quotations.
Visa, Master Card and American Express accepted for customers located in
USA.
To set-up an account, please request our "new account application" form.
GE Fanuc CNC Customer Care
GE Fanuc Intelligent Platforms - CNC Division
POB 8106, Charlottesville, VA 22906 USA

CNC / LASER Products Inquiries:
Fax: 1-434-978-5673 Email: [email protected]
Toll Free: 1-800-432-2621
To reach a CNC Customer Service Advocate, select 1
To reach CNC Technical Support and log a new case select 2
Phone menu info:
http://www.gefanuc.com/downloads/cnc..._phone_map.pdf
Visit our Parts On Line Parts Store at:https://esales.gefanuc.com
CNC Parts Information: www.gefanuc.com
04-18-2009, 05:21 PM
John_B

Re: Fanuc parts direct

Luis M.

I've seen you have offered input on a few issue lately on behalf of Fanuc. Good to see a polite and helpful face to Fanuc as many of us have had less than that shown to us. Hopefully this marks a new direction.
Rgds,
John B
04-18-2009, 05:36 PM
hiiesalu

Fanuc Parts

Luis M.

The Fanuc part FIXED MY OLD MACHINE I am glad they still make some of the hard to find parts, for me $168.00 was cheap compared to the service call, new board ect.
Many Thanks to this forum as another member "G PENA" pointed out what part may be bad.

Reguards
ALan Hiiesalu
Defense contractor
05-07-2009, 04:01 PM
hiiesalu

Quote:

Originally Posted by hiiesalu

I FIXED MY IKEGAI AX25 FANUC 6T AS SUGGESTED 401 SERVO AND HCAL LED LIT.
1.I SWAPED BOARDS A20B-0009-0320 AND THE PROBLEM FOLLWED THE BOARD, "MAKE SURE"!!! THE PLASTIC JUMPERS LOWER LEFT HAND OF BOARD
ARE SET FOR X AND Z ON MY MACHINE THEY ARE SET DIFFERENT. REMOVE TWO CONNECTORS AND RELEASE TABS THAT HOLD BOARD, BEND TABS JUST ENOUGH TO REALEASE TO FAR AND THEY WILL BREAK.

2. IF PROBLEM FOLLOWS THE BOARD THEN REMOVE BOARDS AND REMOVE 1" SQUARE ISOLATION AMP A76L-0300-00317 / T USING A SOLDER SUCKER AND SWAP THESE "BE CARFULL TO REMOVE PART GET ALL THE SOLDER OUT" . IF PROBLEM FOLLOWS THEN REPLACE WITH FANUC PART I PAID $168.00

3. AFTER I REPLACED THE PART AND POWERED UP I WENT TO DIGOS # 800 AND 801 AND ADJUSTED BLUE TRIM POT MARKED "OFFSET" (LOWER LEFT)
AND SET 800 AND 801 TO ZERO BY TURNING KNOB RIGHT OR LEFT

Summary the A76L-0300-00317 / T is a common part failure the proudcure too about an hour and save me the cost of a complete board and or service call

.
05-08-2009, 12:29 PM
greenery_fr

1 Attachment(s)

Hi

Quote:

Originally Posted by Roger Z

Thanks for your reply "hiiesalu". I found a used PCB (printed circuit board) for $250 and just swapped it and the lathe is up and running again. I had located the approximate area of problem, and there were four integrated circuits, which had Fanuc part numbers on them. I was not able to get any schematic diagram or any information from GE-Fanuc. There are several money hungry repair services available, but they can go suck someone else's blood. I will NEVER have anything to do with Fanuc in the future, thanks to the way they operate. I still have the bad PCB and will attempt to repair it if I can get some more information. Then I will have a spare. I am wondering where you got the black cube thing from? Did you order from Fanuc or some other place? They told me that they will not sell to me because I am not one of their authorized repair services. This experience opened my eyes to future machine purchases. If I can not get service information with the purchase, I will buy another brand. Thanks to all for your comments!

This problem can solve
05-08-2009, 05:10 PM
hiiesalu

Right Part

That is the right part, Just make sure it is bad de-solder it and switch it to the other board "carefull to get all the solder out" dont forget to change the jumpers. and set offset trim pot small blue one lower left.
My Ikegai diaonastic 800 and 801 set to zero.
If the problem follows it most likely that part, but the following can happed a HCAL lit led can trigger on the good board when that axis moving.
My problem was intermittent.
Another way to check for a bad part is to use a hair dryer and a can of eletronic freeze and cool the heat the suspect part.

CNC / LASER Products Inquiries:
Fax: 1-434-978-5673 Email: [email protected]
Toll Free: 1-800-432-2621
To reach a CNC Customer Service Advocate, select 1
To reach CNC Technical Support and log a new case select 2
Phone menu info:
http://www.gefanuc.com/downloads/cnc..._phone_map.pdf
Visit our Parts On Line Parts Store at:https://esales.gefanuc.com
CNC Parts Information: www.gefanuc.com
05-09-2009, 07:25 AM
gbowne1

Anyone have any FANUC 6T parts? I'll pay cash for whatever you have working or not.

Greg
05-10-2009, 04:43 PM
yours_prabhat

Quote:

Originally Posted by gbowne1

Anyone have any FANUC 6T parts? I'll pay cash for whatever you have working or not.

Greg

I am having all the parts of fanuc 6 T but I can give you on stand by basis If you required mail me on [email protected] or can call me on +919430737981
Regards
Prabhat Mishra
05-10-2009, 04:48 PM
yours_prabhat

Quote:

Originally Posted by hiiesalu

.

Dear Friend
Please ensure that +15 -15 V 100 V are Ok on the PCB and also check physically that anh hybrid is blown or broken . If the problem persists please mail me on [email protected]
Regards
Prabhat Mishra +919430737981(Mobile phone)
05-11-2009, 05:25 AM
gbowne1

I do not wish to purchase FANUC parts located outside N. america or the USA at this time.

Thanks,
Greg
02-02-2011, 07:53 PM
memogrr18

Pratt & Withney fanuc 0m Alarm 401 almost Solved!

Hey! First of all Thanks to all the bloggers because they helped me to almost solve my problem.
2 weeks ago i bought a 1988 Pratt & withney tape drill mate (a little dinosaur). When i saw it at the shop it was working fine.

But when it was delivered to my place. I installed it and turned it on and OMG! 4 alarms!
401 Vrdy off
x axis not detected and also for the other 2 axis.:tired:

I started by reseting, turning off, on, off on,, and nothing...
so i saw that the 3 axis amplifier had a red led (HC) and obviously, the vrdy led was off...

i saw the diagnostis and there were the bits of the 3 axis in high current...

i checked ground, voltages, phases, inverted phases, and nothing:drowning:

Then i chequed the motors with my multimeter. impedances of .3 to 1 ohms and 3.5 mega ohms with ground... so the problem was not there... I turned it on with servos disconected and there was an issue with the y and z axis. Z axis was because of the break so i conected it. Alarm gone but still y axis.

i checked the diagnostics and there still was an issue with y axis (overcurrent). I swapped the x n y logic cables and the problem swapped from x and y. (drive problem) so i read that maybe the power transistors were busted. I chequed them i even splited them (x and Y) but the problem still in the same axis. :confused:

So i called many companies here in mexico, including fanuc and i received the solution of changing the drive card or even changing the complete drive.

Here the prices:

Only card:
fanucFA: 2,400 USD
other shop: 3,200 USD (chair)
Other Shop: 1,240 USD

Complete Driver
Other Shop: 1,750 USD

I was about buying the complete drive when i read in this forum about the tiny black boxes with a yellow sitker. So i took the advise and swapped the modules from x and y axis and Voala!!!! the problem followed the chip.:banana:

Now i'm looking for someone to sell it to me. i will replace it and see what happens. If it works i'll save a lot of money. Now i see that cnc service is a very good business...

Thanks to all for blogging.:cheers:

Guillermo
02-15-2011, 06:39 AM
memogrr18

Quote:

Originally Posted by memogrr18

Hey! First of all Thanks to all the bloggers because they helped me to almost solve my problem.
2 weeks ago i bought a 1988 Pratt & withney tape drill mate (a little dinosaur). When i saw it at the shop it was working fine.

Hi all, well i changed that component and the mill got alive... i had to type all the parameters... then i had a communication problem: i couldn't input the programs, then i changed the port connection, turned on the second port on and it worked well. :cheers::cheers: