More fun, powered up, Y is moving fine, X axis dead. Swapped the plugs, and X axis moves as Y fine.
Swapped the servo packs, and X axis servo pack is blown, notice a bad fuse, and a bag of fuses taped to the supply (uh oh...) and it pops a new one when inserted. Also noticed it powered up and had good status as a drive on the leds on front and didn't blow its 3amp fuse until it was asked to move axis...
Checks price of used servopack thinking to just pick a good used one up, until I found what they fetch, $750 upwards. Thats not in the budget right now.
Roll up sleeves, strip bad servopack, its already broke so no loss having a look round. I sort of figured the problem is in the power drive side because its talking to everything until it gets asked to move the motor then it all goes to crap.
Found a manual for a older Yaskawa servo pack, back when they had circuit diagrams in. Figured mine was the same power electronics design (maybe with parallel mosfets instead of smaller transistors arranged in a darlington layout), decided the fets were most likely to suffer damage.
https://s3.amazonaws.com/Icarus/DOCU...anuals_489.pdf
Then, to the soldering iron, the FETS labed 1-4 on the silkscreen of the pcb can't be tested in circuit due to parasitic loss, so they had to be desoldered to check. And, out of four, two are blown. Now I have to desolder the diodes to the right and I want to take the bridge rectifier out and test it out of circuit too as I'm getting a funny reading. If its just these fets blown, its a $20 repair.
Theres another pcb on top of this with all the drive wizardy that reads the encoders etc, this base board appears to be the power electrical bits nicely segregated to make things easier.
Heres the datasheet for them. Theyre a standard pinout for mosfets.
Apache Tomcat/6.0.29 - Error report
How do I know two are bad? dvm on diode check if you dont know, theres a runthrough on youtube :-
https://www.youtube.com/watch?v=RBJGOOTEwfU
With two the gate stays on and slowly leaks away, and two it doesn't open at all.
More diagnostic work ahead though, the X axis doesnt work even with the "good" servo pack in it. The display looks like its travelling but physically its not moving, so I suspect whatever caused the servopack to go bad is still there and needs fixing before it strikes again.
All good fun though, learning about the innards quite a bit, and you can't buy learning like this in a book.