Dead motor

[khaos]

Well, I think I have to replace a motor and a driver. I switched the X2 motor to the Y (after pulling it off the bot) and it appears completely dead. I tried the y in the X2 slot and no action.
How does one remove the driver from the board for replacement. I will be buying 2 on Monday. and a new stepper.

Apparently, I need one for my indexer as well...

Anyone have any resurrection incantations handy? :P Other than that does the prognosis sound valid?

[dubliner]

Joe, although highly unlikely by the sounds of it, you'll want to verify that the wiring connector on the motor is OK. That means cutting off the heat shrink & swapping it to a working one. This might be ill advised if the motor is still warranted, if not then...

[Brady Watson]

Joe,
A looong screwdriver. I made one out of 1/8" steel welding rod. Geckos don't usually go bad if they were previously working for more than a month or 2 straight. If they go bad, they usually go bad quick...weird but true. The red & black label motors almost NEVER go bad. I'm pretty sure that the number of motors that have EVER gone bad have been less than 10 TOTAL over the last decade with at least 20,000 of them going out SB's door. So your motor is most likely fine.

I cannot stress the importance of proper wire maintenance, configuration and strain relief for the PRT/PRS Standard line of tools. All tools should be properly wired, but the Standard tools get finicky if things are not right. Check ALL wiring and even re-seat the wires going to the 'faulty' motor with the little candy cane looking Wago tool. If you do not have a Wago tool, get one from SB...get 5 of them & tape them to the wall and various other places. They get lost easily.

And lastly, check to see if your tool still falls under the 2yr warranty.

-B

[khaos]

I will call SB on Monday. However, my warranty may be impacted by the following... http://www.talkshopbot.com/forum/mes...tml?1210783456

[khaos]

OK, so the Motor IS dead. Also the driver is dead. This damage is from the insulation on the stepper wires being melted away allowing a full short. Notice the capacitor is actually blown out!!!

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After removing the driver I decided to inspect the bottom of the controller board. Unfortunately there was serious damage.

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Which I promptly made repairs to in order to avoid the wait and the cost of a new board.

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This PCB is very 'open' and one sided. What I mean is that there is basically only printed circuits on one side of the board and the gap between runs wider than most. These all helped facilitate the repair.

The little black spot on the green wire is 'liquid electrical tape' over a spot where the iron touched the insulation. :/ Cut the loose circuit tape, clean up the board... The opposite side of the board is fine after the repairs. This is critical as the heat from a repair like this can damage elements on the other side. Connection pins like the ones that the geckos connect to can move and become too long or short. All in all not for the feint of heart.

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I have replaced everything and should be surfacing the spoil board first thing tomorrow! WOOHOO!!

The bot is moving smoothly and freely and I am thrilled to be so close the 'up and running'

My humble thanks to all,
Joe

[Brady Watson]

I'm suprised that the tool worked at all considering that everything was grilled to death in a fire...

-B

[khaos]

Well, the control box was in a seperate cabinate. So no heat or smoke damage just the short. not that thats anything to sneeze at...

[mariss]

Joe,

Wow! I've never seen such a totally toasted G203V. What drew my attention is the hole in the big brown capacitor and the blue resistors (3rd pix, just to the left and below the top 4-40 screw).

1) Two of the 3 blue resistors are toast, the 3rd one isn't. Each of toasted resistors serviced the motor windings, 1 sense resistor per winding. That means both winding power stages failed at the same time.

2) The 3rd resistor should have burned open (it senses over-current) to limit damage. It didn't. This would only happen if the internal fuse is bypassed somehow (power entering the drive on a motor connection).

3) The fuse (a green part standing up near the top of the brown capacitor) should have blown and prevented any damage from happening.

4) The traces servicing winding A are vaporized on the green printed circuit board.

5) Most interesting is the hole in the brown capacitor.

Looking at what is and isn't damaged leads to a possible cause for all this destruction; something like 115VAC or 220VAC somehow touched one of the motor winding A wires. The reasoning is the G203V is protected against any possible short circuit except for contact to a power source on other than the power input terminals. Anything else would have caused the G203V to shut-down or worst-case, blow the internal fuse with no other damage.

My reason for guessing the source was AC is the capacitor has a hole in it (lower right side). Only an AC voltage can do that; DC less than 100V would have caused no damage to the capacitor.

You might want to check if somehow an AC wire got loose and made contact to the green printed circuit board.

Mariss

[khaos]

Mariss, Thanks for that in depth analysis!! I truly appreciate it. I am an ex US Navy ET so I love that stuff!! I would not doubt that there was AC contamination on the line. Look at these pics: http://www.talkshopbot.com/forum/mes...tml?1210783456

Joe

[mariss]

Knowing why a drive blew is just as important as repairing it. Thanks for the pictures, they made it possible to hazard a guess.

Mariss