Power on problem with a yaskawa VM3 in a Matsuura RA3F

Hello Forum,

I have looking for some help with a 626VM3 model CIMR-VMW2022, basically the 200volt version of the spindle drive. Over the past year the drive at power on does not come up. In that the 7segment display that gives the error codes and such just stays unpowered. When trying to bring up the rest of the machine(Matsuura RA-3F) I get a spindle pg error. Basically the drive is not on. If I sit and wait like 10 minutes with the main power on but the power on the controls has not been pushed the drive will come on. The display will turn on and then I can power the machine with the controls and it works normally. I can wait 10 minutes each time, but Im sure this problem will continue to get worse. I cant tell if this is some kind of self heating issue where it powers up after something makes a connection on some power supply or what. I was thinking it might be a 24vdc power supply that has bad caps, but it seems like after coming on I would have an error message if the supply voltages were out side of their limits. I know there is at least one thermistor I found on one heat sink. I have not messed with any of that stuff as of yet. Trying to get a internal wiring diagram from Yaskawa for the gets of VM3 is not possible or so it seems. Does anyone have any ideas or thoughts one what to check in side that thing or wiring diagrams for the guys, and or schematics for them.

Thank you for any help!!
Matt

The Yaskawa drive has its own internal low voltage power supply. If it is failing you will not get any alarm on the drive itself because there is no low voltage to drive the alarm display. A device that will finally power up after having power applied for several minutes is very often bad electrolytic capacitors in the low voltage supply portion. Identify what portion of the board is the power supply and note all the electrolytics. Order replacements from Digikey and swap them all. Probably less that $10 in caps will put it right.

Thank you VancBiker,

Yeah Ill look into those caps and get some on order. I am also going to reverse engineer that board. AVR00379 as its a single layer board. The output side of the supply is based upon the LM7805, 7815, and 7824 parts so those are pretty easy to deal with. Its the offline switcher that is controlled with the JRC S00115 where the unknow stuff happens. There is also a thermistor on the heat sink for the LM series linear regulators. Does anyone have a data sheet for the JRC parts? Ill post hopefully a schematic in a few days.

Thanks again Vancbiker!!
Matt

VM3 Drive powersupply issues.

Hello VancBiker,

Ok, I got it. I tried as you suggested and replaced caps. I actually found a bad cap. C8 on the high voltage side was bad. Though its an Aluminum electrolytic and I dont think it was causing enough of an issue to bring the supply down. What I did end up discovering was the output voltages were pulsing at a few hz. They were ramping up to their voltages and then shutting off. This is consistent with a over current condition and the supply shuts it self down. Since this supply was running after a few minutes it was hard to find the issue with that specifically. I checked the 0.33ohm current sense resistor and it was in good condition. After building a schematic I found three feedback mechanisms. One is for the thermistor, one is for the output voltage of the supply. I did not verify how the third was used. What I discovered was the supply voltage feedback opto isolator had either warn out or had failed. Leds in Opto specifically in power supplies can go bad or weaken. The Led starts putting out less and less light. Replacing the Optos solved my issue and the drive now power right up.

Im attaching the reversed image from the pcb as if your looking though the board with some of my notes on it. Data sheets for some of the active components. I was not able to find the datasheet for the old JRC S00115 which is the hybrid switcher controller device.

Im attaching my files, design files, pdf of the schematic I created. Its not perfect and may have errors and is ugly. Also Cadence capture design files for the schematic are also included as well as data sheets for the parts on the board.

If someone else reading this message needs to replace a AVR000379 consider sending it to Percision Zone. These guys can fix it if you cant or dont have the time. I should have done this but learned about them to late. There was also a warning by them about the old contactors on the output of the VM3 drives. If you have a HV-150AP2S that you should replace it with a HV-150AP4 as they are the newer version. I guess all of the old AP2s have a failure mode that will take out the VM3 drive. Was news to me.


I hope this helps someone else. Thanks again VancBiker.
Matt

Ok, this forum does not want to let me upload files of much size. Im attaching a google drive link for a zip file with all the info in it.

Excellent troubleshooting and repair!!!!

Hi,

I have a Hurco BMC40 with Linuxcnc. The spindle drive (Yaskawa 626VM3)has the same power supply.
It was difficult to get started, just like yours. This week it did not start at all. Changing the electrolytic capacitors didn't help.
I've changed optocouplers like you, and miraculously, it works!
However, there is still an F600 error at startup, but by switching off and on again it starts normally.
On output on pin 7 I have only 20v instead of 24v. Could this be the reason of this error?

Thank you very much for sharing!

Hello,

I'am getting alarm F905 on Yaskawa 636, i have check thermistor and it's OK, it changes resistence when temerature change. Has anyone solved probem? where to search next?

Link on google drive is not working. Cay You restore link, or send me photos via mail.

Thanks in advance