three dead geckos sittin inna box

[dertsap]

i could use some helpfull thoughts , mine are a clouded if not smoked

this is what ive gone and done to my gecks
ive got some new motors and i wanted to connect one and try it using a separate 12v power supply for that motor (z axis),the other two are 48v, in my haste i connected the 12v+ to the common (WRONG) and the neg to the power neg(right) ,after realizing no axis will move i quickly powered down , ive got two blown fuses on the x and y axis that were running before this mishap ,after numerous times of trying to run the x and y,i stripped down to bare bones and rewired everything
tryed running on three different computers and nothing ,
the motors are getting power but won t move ,the led lites up on the driver ,
is it possible that i could have cooked the logic in all three drivers , i can see smoking the one that was wired wrong ,but all three ?????????
the only thing ive done differently is what i had already stated other than that it was a perfectly good running system , all the motor power and logic power were shared between the three drivers before this (two separate power supplies 5v logic supply , 48v motors supply )
i was all exited to try my 770 oz motors ,this bites !!
tomorrow i'm going to buy a new parrallel port cable and hope for the best , though im pretty much numb at this point

any ideas ????

[phomann]

Hi ,

There is no connection between the step/dir, common inputs and the Gecko electronics. There are Opto-isolators in between.

If I understand correctly, Connecting 12V to the Common terminal and Gnd to the Gecko Power Gnd terminal should not harm anything, UNLESS you 12 Motor supply is not isolated from your breakout board logic ground.

The curent may have found a path from the common terminal through the opto diodes into your breakout board back to your power ground.

My guess is that if the Geckos are damaged it is only the optos. If they are damaged, then your breakout board may also be damaged as well. Then there is your PC parallel port. Did you feed 12V into it?


I'm only guessing though. I'm sure Mariss can give you a better explination.

Good luck.

Cheers,

Peter.

[pminmo]

What point are you calling common? The isolated input 0V side that goes to the pc lpt port pins 18-25?

[phomann]

The Gecko 'Common' terminal is the +ve suppy for the step/dir opto diodes. It is usually connected to +5V referenced to the PC parallel port ground.

Then to step the drive, the step input is driven low.

Peter.

[Mariss Freimanis]

Do you want the good news or bad news first?

1) Good news: The drives are probably healthy or at worst have a blown opto.

2) Bad news: The PC's parallel port was very unhappy with what you did.

Mariss

[dertsap]

Originally Posted by Mariss Freimanis Do you want the good news or bad news first? The PC's parallel port was very unhappy with what you did. Mariss

not as unhappy as i am ,
though i dont want to loose the pc , the drivers are my concern , pc's are cheap when bought used

i changed the parallel port cable and the best i can get is a hiss from the motor ,i currently have it connected to my home pc ,which should send the signal ok
how do i repair the opto ?

[dertsap]

so a simple phone call solved that last question i had , caught me off guard , gotta love that kind of service , definitely a well stood behind product
i'll see if i m missing something here and verify if they are indeed tosted , then send them off for repair

thanks guys

[motomitch1]

You could fix the pc with a PCI parallel port add in card

[dertsap]

i'll try that if i need to i'm hoping that its ok , there are some second hand stores around here where that stuff is a dime a dozen ,
i'm going to keep my fingers crossed

[Mariss Freimanis]

My answer was predicated on how the PC ground and your 12VDC grounds were connected. If both were tied together your PC took a hit. PCs don't do well with 12V applied to an output.

The drives probably took a hit too but it's not that bad. It would have blown out the step/direction opto and the associated 200 Ohm LED current limit resistors.

These are non-fatal damages that are best repaired here and we repair our drives for free. The damage is to surface mount components so it's better we do it having the right equipment. Send the damaged puppies back, we'll fix and return them to you.

Mariss

[dertsap]

thanks Mariss

we fix it free" are the words of a truely honoured product and company ,
it isnt exactly something that rolls off of a lot of tongues

i have one question , if the step/direction opto is blown would the motor turn at all , at this point it seems at least one of the drivers is turning one direction but slow and very rough and the motors hisses ,i have to test the other two ,but i had roughly the same results
ive got a new port cable and the breakout board is bare bones basic
i am using another computer to test it on so the signal should be good
should the motor turn or should it not move at all

[Mariss Freimanis]

OK,

Quick test. Disconnect the main connector, get a multimeter and set it to Ohms. Connect a probe to COMMON, then measure COMMON to STEP, then COMMON to DIRECTION. The reading you want to see is 1.2K give or take 5%. Get that and the drive is probably OK.

If not, send it back. It's 15 seconds out of my life if it's OK, 5 minutes if its not. 2 weeks out of yours though. 1 week to get here, 1 week back.

We only do returns every Friday afternoon. Not enough returned drives per day to put on the trouble-shooting hat unless there's a number of them. Takes a week of returns to be worthwhile.

Include a note describing the situation because I really hate mystery drives that show "no problem found". It's a lot of extra work chasing a problem that does not exist.

Also it puts in a real bad mood and makes me really uncharitable if the bottom of the drive is covered heatsink goop I have to clean off before I can plug it into our really cool, computerized, pogo-pin equipped, pristine and spotless teststand. Be kind to me, otherwise I won't try so hard on your 5-years out of warranty drive.:-)

Mariss