[GTFreeFlyer]

My G540 was working just fine until it decided not to. It doesn't have that much use on it. Here's what is happening:

1. Red "fault" LEDs illuminate when power is turned on.
2. Multimeter probes between pin 10 and 12 show open and closed circuits when the E-stop button is switched. Button is working.
3. Disabling the charge pump doesn't change the results. I tried this with and without the DB25 connected.
4. Screen in Mach 3 always shows "external e-stop requested"
5. Multimeter probes between pin 1 and pin 12 show a small fraction of a volt. (limit switch connected and grounded)
6. Multimeter probes between pin 2 and pin 12 show a small fraction of a volt. (limit switch connected and grounded)
7. Multimeter probes between pin 3 and pin 12 show a small fraction of a volt. (limit switch connected and grounded)
8. Multimeter probes between pin 4 and pin 12 show 48V!!!!!!!!! This is without any wire connected to pin 4 input. Is it supposed to be 48V? Was expecting 5 or 10V?
9. Multimeter probes between other pins show 5V as I expected.
10. Multimeter probes between pin 11 and pin 12 show 48V as expected.

The only thing I recently changed in my setup was adding a .1uF ceramic cap to each of the 4 inputs (pins 1 thru 4) and tying them all to pin 12 ground. I've removed the capacitors since then, but no luck getting back to my original working condition.

[Khalid]

I had a similar problem few hours before. I connected the Estop Ground to common ground of power supply. Make it sure that you have connected Estop ground at Pin-12.
In MAch3 also check wether your Estop is "Active Low" or Active High..

[LeeWay]

Another thing to test is to disconnect one motor at a time while powered down and try the start up.

I had one loose wire inside one of the plugs I installed (db9) and that was what lead me to pinpoint the trouble.

[Khalid]

Also check your Estop button. Is it down?

[GTFreeFlyer]

I was sure it was a bad DB9 cable, but turns out my problems don't lie there.

I pulled out all the wires, and all that is connected right now is:
Terminal 10 jumpered directly to Terminal 12 (no E-stop button in-between). Continuity check between the two terminals checked out good.
Terminal 11 connected to +48 VDC supply
Terminal 12 connected to ground and to Terminal 10

Charge pump is disabled.

Red fault LEDS come on when power is applied.

I followed steps 1-3 in the G540 manual, and I should have a green light at this point, which I don't.

What is happening?

[LeeWay]

I'm not sure if a blown fuse inside will still show a red fault or not, but you can take the cover off and do a continuity check on it.
If it is good, then you might want to contact Gecko about repairing it for you. I have had a few different drives from them repaired or replaced for free. I think they will automatically give you one free repair if your fault.

[GTFreeFlyer]

I'll have to get in touch with them I think.

I just removed the G540 from my CNC machine and connected it to another power supply, with the minimum connections required on Terminals 10, 11 and 12, and I still got the same result.

I'm going to open it up now and take a look.

[GTFreeFlyer]

Look what I found after I opened up the G540...

It appears that a clipping from one of the leads got wedged between two pins of the MOSFET. I removed it, and tried all the minimum connections again. This time, no red LED, but no green LED either. The 4 LEDS near the axis trim pots come on (as before) and are illuminated red. I hooked up all the other terminals and powered up Mach 3 and my CNC, but I still have no green LED, and I'm still getting the "external E-stop requested" message. I think something on the G540 board got fried.

Thoughts?

[LeeWay]

This is from the troubleshooting chart that you have probably seen.
SOLUTION: Verify that the power supply is plugged in correctly to the 12-PIN TERMINAL BLOCK. If it is and power is applied with no LEDs being lit up, you have most likely had the fuse blow open. To check the fuse you must first remove the cover. The fuse is located by the 12-PIN TERMINAL BLOCK on the underside of the motherboard; you can pull the motherboard off of the G250 drives to access it. Next, use an ohmmeter to check for continuity on the fuse, which looks like a green 1/4W resistor. If the fuse it destroyed you may contact Geckodrive for replacement fuses or order spares online with part number F23118-ND from Digikey.

[GTFreeFlyer]

Yup, I checked that one when I had opened it up. Fuse is still good. Thanks.

[Khalid]

I think your MOSFET IRF540 is damaged. My suggestions:
1- Send the photograph to Gecko personals i.e Marcus etc and ask their opinion.
2- If you do not want to send the drive to Gecko then replace this MOSFET. Its readily available in Market. Make it sure you purchase IRF540 instead of IRL540. Further ask the Gecko of replacement of this MOSFET.

[GTFreeFlyer]

I was reading about MOSFETs and it seems that shorting the gate and drain (as what happened in my situation) won't damage the MOSFET? I'm not 100% sure, but if this is the case then damage is somewhere upstream or downstream of the MOSFET. I can easily swap it out and am comfortable with solder rework, but I don't want to be messing with the original board unless I hear from Gecko. I contacted their tech support thru email. We'll see what happens in the next few days...

[Khalid]

That's a good decision .. Don't forget to post the outcome.. Yesterday i wrongly connected the Power wiring to Gecko G540.. They have not inscribed the number anywhere on the connector or the Aluminum casing.. I thought that the G540 may be dead but after correction in wiring it is working right now. They have added good protection in the G540 ..
Mariss and Marcus are very good to deal with...I hope you will be on track very soon.

[LeeWay]

I had to have a drive repaired at this time of year a couple years ago. With the Holidays, it takes a little longer than usual, but they will get it done for you. Even if I was able, I wouldn't touch the first Gecko that had trouble. I would send it to them so that they can test it all out and determine the exact cause, though it seems pretty obvious on this one.

I am the cause of Gecko including a blurb in the manual about not switching the DC side of the power supply to a stepper drive. Mariss stuck with me through a couple problems with Gecko 203V's and he finally figured out that I was switching the DC side without ever even seeing my setup. Now that is troubleshooting. That inrush current can kill even the unkillable 203V. Make a better product with numerous safety mechanisms and they will just make smarter idiots to defeat them.

[Khalid]

Lee,
"Not switching the DC side of the power supply to a stepper drive."
Can you tell us How you were switching DC side of power supply?

[LeeWay]

Sure.
I always have a switch on the AC side or incoming supply to the power supply. In that panel, I also had a switch between the power supply out (DC) to the Gecko's.
It is a 72 VDC supply @ 12 amps. I would turn on the main power switch first and let Mach 3 and the computer load. Then I would hit the switch on the DC side. It would not always kill a drive, but wound up killing two or three before it was over and it was always the same one. I can't recall if it was the one closest or farthest from the supply. The result was that inrush current was too much for one of the components on the drive somewhere past the fuse.

So...., the moral of this story, don't put a switch on the DC side of the PS between the PS and the drive.

Mariss stated after it was over that it never occurred to him that someone would actually do that. That is what I meant about smarter idiots.
I can generally find a way to screw something up. It might take me all day, but I have a knack for getting there.

[Khalid]

Lee,
Now i understand what happen. Thank you for sharing the experience.

[GTFreeFlyer]

So I just happen to live walking distance from Gecko and went over there today. I met Marcus and he took the G540 in for diagnostic checks. 5 minutes later he came out and told me the motherboard needed to be replaced and asked if I could wait 15 minutes. 15 more minutes passed and he replaced the motherboard with a new one and upgraded me from a Rev4 to a Rev8 G540 and I was on my way. Absolutely amazing and I am so glad I own a product backed up by someone like Marcus.

Thanks to you guys for trying to help me out and a big thanks to Marcus as well if you are reading this!

[LeeWay]

Wow. Small World.
Glad they took care of you. I knew they would, but had no idea how fast.
Merry Christmas to you.

[Fastest1]

So I just happen to live walking distance from Gecko and went over there today. I met Marcus and he took the G540 in for diagnostic checks. 5 minutes later he came out and told me the motherboard needed to be replaced and asked if I could wait 15 minutes. 15 more minutes passed and he replaced the motherboard with a new one and upgraded me from a Rev4 to a Rev8 G540 and I was on my way. Absolutely amazing and I am so glad I own a product backed up by someone like Marcus.

Thanks to you guys for trying to help me out and a big thanks to Marcus as well if you are reading this!

Mariss