bensmall

Ouch, potential for track corrosion in the mix too huh. At least there are not too many vias that can have rotted out.

 

What led you to swap the sense resistors out and what state were they/ meter readings did you get beforehand on their connections? Also, are there any now comparative differences measured between a known good driver circuit on the board and the faulty driver one?

 

Does it seem like the 3692 is working in conjunction with the socketed driver chip for each attribute for microstepping (e.g count up how many there is of each?)? Some legs look quite unhappy there too, and obviously if the issue is not with 'usual' chip, swapping the latter wouldn't appear to help.

 

The fault sounds very physical, but if you reckon it's definitely on the PCB then one might assume that difficulties are because the drive control/sense etc is preventing the correct operation of the motor by being somewhat confused.

I Measured the sense resistors in and out of circuit and they showered a higher resistance of 2ohms and not 1.5 ohms so swap them as a just in case measure

as for the 3692, I'm not to sure as the oscilloscope I have to hand dose not have any probes, unless its something I can measure with a multi-meter I cant tell if this is the fault.

is there any faults that happen as standard with the mac 500/00 pcb ?

Such a long time since I worked on these. If you are convinced it's a component level issue on the PCB, best thing is to post up some decent resolution pictures of both sides of the board. I have a hazy memory of a lot of driver chips fed off a main controller, but it would be easier to see what's what.

Hope these help, please excuse the bad soldering only had a TS80 to try and get the resistors swapped out

https://ibb.co/nsptYc7

https://ibb.co/4RhL39J

https://ibb.co/fdw5Nyz

https://ibb.co/BzHNtvB

Have you absolutely eliminated any other possibility off the PCB, including the correct physical setup of the Pan and Tilt motors?

Hi Rob

yes have swapped over a working PCB from another mac 500 & mac 600 and all motors on both fixtures are working 100%

Hi All

Hoping you can help I have a pair of Main PCBs one for a MAC 500 and One for a MAC 600 E-NT

both have a slight issue

mac 500 Pan Driver is an issue it pans for 1 second then starts to judder and is very hard to move by hand ( have swapped looms and driver chips with tilt, at different times and fault stays with driver socket. Motors all check good, have replaced all the 1.5Ohm resistors for the Pan Driver socket and had no change)

Mac 600 Tilt Driver issue driver tries to move the tile motors but is unable to and it Very weak to hand ( Had done fault finding the same way as above fault stays with the socket again and the motors both work perfectly on the Pan driver chip)

any knowledge you have about these PCB would be appreciated and of great help

Ben