[KPBadger]

Dear All

i think i have managed to blow a servo driver ( Y axis ) in our GCC spirit.

i was using the rotary axis, when the Y axis started behaving erratically.
normally using rotary axis, the y locks at the central position, but it instead began creeping to the top of the table. then suddenly - WHACK it came down to the bottom of the table faster than ive ever seen it move ( glad my fingers werent in the way! )

But...that was the end of the Y motion.

have swapped the motors, and deduced that the motor is fine,
but no response from the y controller.
( just goes to call your distributor screen on startup )


NOW the question -

anybody know how much a new motherboard costs!?!?!?

anybody attempted to repair the servo driver ?

thanks

KPB !

[Exsecratio]

Can you reverse the X and Y drivers KP? I'm not too familiar with the Spirit but from memory it has separate driver cards for each axis.

Will at least show if it's Mainboard or cards price wise, no idea....Chinese based stuff trends to be around £50 for card drivers and £250 to £400 for mainboards here.

best wishes

Dave

[KPBadger]

Hi Dave

thanks for your reply.

i'm maybe being thick but it looks like 'everything' is on the one motherboard.

im certainly not an electronics expert, or even approaching it - but the motherboard has 3 big IC's with heatsinks which im presuming are the backbone of the servo drives?

on our chinese machines its nice and modular so each stepper driver is a seperate box, but unless im missing something the spirit is not built like this.



cheers!


kpb

[Exsecratio]

Sounds like it could well be one unit my friend, Leave it with me for 24 hours and I'll make a few calls to see if their is a more economic resolution possible rather than a replacement board.

best wishes

Dave

ps: I can just about wire a 13amp plug so I'm no electronics guru either, but I know a man who is

[Rodney Gold]

Check to see that the little blade/tab on the Y axis is *actually* interrupting the optical reader that tells it where home is .

[KPBadger]

Thanks Rodney,
have been into the diagnostic mode ( hold autofocus button on startup )

y motor diagnostic, gives readout on the servo position, so the motor is reporting its position, but no power to drive the motor.

have checked also the optical limit stops, but cant seem to find an issue there.

also i plugged the motor from the defective y axis in to the x axis and it powers fine.


Dave,
any info you can glean will be gratefully received.




im going to take the board out to study it more closely!


thanks
KPB

[Rodney Gold]

Before that , just try taping a small extra piece of paper to the end of the home poisition tab that interrupts the optical sensor so it protrudes more into the slot , ours "looked" ok but wasnt and we had similar issues to yours.

[KPBadger]

Hi Rodne,

have had a look at the sensors, but dont think that is the problem.
unless i somehow broke the sensor when it crashed home.

will try plugging in a sensor from elsewhere


i must admit i had not thought about that, its always good to have more pairs of critical eyes on the problem!

ta.

KPB

[KPBadger]

rodne,
had the meter on the sensors. all performing as they should.
0v when open
+5v when closed/interupted.

you got me thinking that maybe i had physically damaged the y limit sensor when the gantry had crashed home - but doesnt seem to be the case.


thanks
KPB

[Exsecratio]

Hiya KP,

Made a few calls and it's *apparently* not an *unusual* problem under some circumstances. I've asked Tony at Tactical Electronics to see if he can source a mainboard at any better price than the normal retail. I'm trying to get one on loan that may be useful for testing

best wishes

Dave

[KPBadger]

Dave, thanks for this.
much appreciated you taking the time to make these enquiries!

spoke to grafityp and gcc mainboard is currently about 400+VAT gbp.
so maybe not quite as horrific as i had imagined, but still an expense i could do without.

hoping to get one of our electronics boffin friends to have a look re a repair.

but might be more trouble than its worth. fortunately we have the other spirit running so we can still get the jobs done in the meantime.

kind regards
stuart

[KPBadger]

Ive had time today to get the probes on the main board....

"think" i have found the problem!

so the mainboard has 3no. L6203 chips fixed to big heatsinks.
in my laymans terms these are indeed the servo motor drivers ( might not be the correct terminology)

now i was confused because there are 3 since the z axis is stepper driven, but of course! X, Y, and..... rotary.... are servo.

from left to right as you look at the board the 3 drives are X, Y, Rotary.

a quick google search gives us a datasheet for that L6203 chip to identify the pins.

L6203 datasheet pdf datenblatt - STMicroelectronics - DMOS FULL BRIDGE DRIVER ::: ALLDATASHEET :::

and using a multimeter and the laser's diagnostic mode ( hold autofocus during start up) i have found that these chips are receiving some input, but the Y driver is outputting nothing.

thus confirm it is blown, and satisfy myself that it is worth proceeding to replace the chip and hopefully it works!

cost for new chip - £4.00 !

so i truly hope that fixes it,

will update when the chip arrives and i have time to replace it.



thanks to all.

KPB

[KPBadger]

hi everyone

just to confirm that replacing the 'suspect' L6203 IC has repaired the GCC spirit to full working order.

if anyone has such a fault with their machine ( dead X,Y,or rotary ) then i suggest following the diagnosis here after ruling out motor fault.

the part is easily obtained and straightforward to replace with a soldering iron.


kindest regards




KPB.