NOTES FOR REPAIRING or REPLACING a defective PMDX-134

The PMDX-134 has been discontinued due to unacceptable failure rates 
of the connectors required to mate with the Geckodrive series of 
stepper motor drivers. This is because connectors manufactured after 
regulations prohibited the use of beryllium copper in electronic parts 
are not as reliable. Spring loaded contacts made without the use of 
beryllium copper are not as strong unless they can be designed to be 
larger or there are more contact points. Such changes would not be 
mechanically compatible in this application.

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Source for repair parts if you wish to continue fixing board by using 
the newer connectors without beryllium copper contacts.

Digikey ED1682-06 vertical 6 pin male pin strips for motor connectors

Digikey ED1614 female 3 pin mating connectors for male pin strips, 
      use with PMDX-134 or Geckodrives themselves for cables to
      stepper motors, use in sets of 2

Digikey APC1234 vertical 12 pin female sockets on underside of PMDX-134, 
      mate with Geckodrives

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Hints on replacing a PMDX-134 with direct wiring from a PMDX-126 to 
Geckodrive G203V, G213V or G201X stepper motor drivers.

1) Wiring for the Geckodrive "Power Gnd" and "18-80 VDC" should use 
18 AWG or 16 AWG stranded wire. These wires should go directly from 
each Geckodrive to the power supply. 

Do not "daisy chain" the connections. 

Do not put fuses in these wires, as sudden interruption of the connection 
would deprive the Geckodrive of a place to dump back EMF and excess 
voltage could develop inside the Geckodrive as the motor dumps its 
internal magnetic field.

2) Move the "Current Set" resistors, if any, from the PMDX-134 to pins 11 
and 12 of the corresponding Geckodrive. Operation without a current set 
resistor will configure the drive for 7 amperes.

3) Connect the stepper motor wires to the Geckodrive in the same order 
that they were connected to the PMDX-134. If you interchange the two 
wires of one coil, or swap one coil for the other, your motor will turn in 
the opposite direction.

4) Connect the "Common" on the Geckodrive to the PCgnd on J1, J2, 
J3, or J4 for that drive.

5) Connect the "Step" on the Geckodrive to the odd numbered pin
("3","5","7", or "9") on J1, J2, J3, or J4 for that drive.

6) Connect the "Dir" on the Geckodrive to the even numbered pin 
("2","4","6", or "8") on J1, J2, J3, or J4 for that drive.

7) Normally you do not need a connection to the "Disable" terminal 
of the Geckodrive. If you wish to provide the ability to free-wheel the 
stepper motor while the driver is powered on, provide a switchable 
connection to the PC+5V terminal of J1, J2, J3, or J4 on the PMDX-126.

8) Additional support for using Geckodrive products can be found here:

https://www.geckodrive.com/support/