X-Axis and Board Problems

Hi,

The fact that the motor will operate in one direction only seems to point to a problem with the "direction" input to the stepper drive IC on the control board. This IC is probably OK as it will drive the stepper motor

Check that all the connectors are fully mated (UC100 and parallel interface board). If these seem OK then check continuity through from the 25 way "D" connector pin 2 through to the control board connector SV1 pin2. It is also worth checking that pin 2 isn't shorted to ground ("D" connector pins 18 through 25). Use a decent test meter to do the checks so as not to risk damage to integrated circuits on the control board

If the continuity from "D" connector to pcb is OK, and there is no short to round, then your only resort is to substitute known working parts. Your local supplier should be able to help you with this.

However ...... if you are into electronics, you could try manually connecting the X axis step and direction pins to ground at the control board connector SV1 to simulate driving signals. The SV1 connector accepts .025" square pcb header pins.

I can give you more info later if you want to do the simulator tests.

Peter

Thank you Peterg1000.

Can you send more info, please? I will try if I can follow your instructions.

Thank you again.

Hi,

Need to know if you have a good test meter, and if you can make up 3 test leads to allow access to the step, direction and ground pins on the control board SV1 connector. One end of these leads should have a 0.025" (0.64mm) square pin attached so as to patch in to ground, X-step and X direction pins on SV1 - make the leads at least 8" long to bring them clear of the Stepcraft and fix them down with tape so they cannot move and accidentally touch anything.

When tested with the voltmeter, each of X-step and X-direction wires should read between 4.5 and 5 volts when power is applied to the control board. These pins have a 47kohm pull up to the +5V logic supply - the meter load will cause the measured voltage to be somewhat lower than 5V.

Momentarily grounding the X-step lead should make the x motor rotate in one direction. Now ground the direction lead and repeat the X-step grounding process. The motor should now rotate in the opposite direction if all is well.

If this test fails, then the probability is that the control board has an internal fault and would need to be replaced. If the test passes, then a continuity check on the parallel interface board should be done - there may be a broken track on the X-direction line.

If all is well there, then suspicion must fall on the UC100 module. No meaningful checks can be done on this unit without specialist equipment, and a substitute will be needed.

A long winded explanation of a very simple procedure - sorry, just don't know how skilled you are!!

Whatever you do, DON'T inject any external voltage into the parallel interface connector.

Peter

Just heard from my seller. Its USD200 for a replacement board.

Is there no warranty for this machine?

Hi,

So you did the simple tests and proved it was the control board? Do give some feedback!!

I'm sure there is a warranty on all parts of your machine - you need to talk seriously with your supplier if your machine was only purchased recently. $200 sounds rather high to me, but then what do I know!!

Peter