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Just purchased  a Lionel Legacy SW8 Diesel Switcher- a Conrail #8657, Lionel #2133590, and after either programming  forward and reverse operations, or manually performing forward and reverse operations the engine just sits there, and the cab lights blink on and off. I still have sound, and can here the rpm's go up or down while I turn the CAB2 wheel. If I power down and restart, all is well. I've tried TMCC and Legacy control. Other engines- ET44AC Diesels and a Legacy Cotton Belt Diesel operate just fine either programmed or manually, starting and stopping, forward and reverse.

I'm suspecting faulty board??  Ready to return. Any suggestions?

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No, not a faulty board. "the cab lights blink on and off." Indicating a stalled motor detection has kicked in.

That is exactly how it is supposed to work to protect you and the motor. If it cannot read the tachometer of the motor spinning (or the motor cannot achieve the commanded speed step RPM) then it assumes the motor is jammed and cannot spin. Rather than the motor control circuit ramping up the voltage (PWM) to the motor trying to achieve the commanded RPM but cannot and thus possibly burning out the motor, it stops and blinks the cab light, and then locks out any further motor drive until reset.

" If I power down and restart, all is well."

Correct again- normal and expected. That is how you reset the locked motor state. You can also hit 0 on a CAB1 or CAB2  reset button to reset via TMCC/Legacy. Power cycling track power completely (full off and then on) either in conventional or even in command also resets.

Note: you can cause this fault to be tripped if the track voltage is lower (example less than 18V) than the current speed you are commanding requires and the motor cannot achieve that speed- again, the controller assumes this is too much load and could burn out the motor so it locks out motor drive until you power cycle.

Last edited by Vernon Barry

I tried pulling the manual for your engine (SW8 series) from Lionel support but got document not found.

That's OK because I know for a fact your engine uses the same board set- LCP2 and thus the manual from my SD70MAC is valid as far as this error and cab blinks and motor drive.

Page 44

Locomotive diagnostics

Our locomotive includes built-in diagnostics to monitor the condition of the main drive motor. If a problem is detected, the locomotive's cab light will blink a diagnostic code. If you see the light inside the cab flashing, press RESET (for LEGACY operation), 0 (for TMCC operation), or DIRECTION/power interruption (for conventional operation to attempt to clear the problem. The locomotive will immediately check itself again. If the problem persists, the cab light will blink the code again.

Number of Blinks Diagnostic Code Description

1 Main drive motor stalled.

Here was a similar topic with a recent engine where this safety feaure was discussed

Note the end result was the user had less than 18V on the track and thus invoked the low track voltage problem causing motor stall detection to kick in.

Again, in the manual on page 6 of TMCC operation, this key step.

  1. Increase track power voltage to full power (no more than 19 volts AC). If a circuit breaker trips when you turn on the Lionel power supply, check the wheels of your locomotive to make sure they are all securely on the track. Check to make sure the track is free of all metals that may cause a short circuit.

Sadly it doesn't warn you of the consequences of what less than full voltage can invoke - stalled motor detection, especially when the motor cannot reach the commanded speed at the current track voltage.

Last edited by Vernon Barry

Obviously, do the common sense check and ensure the gears are not jamming (ballast or something else binding the driveline).

However, since you said it did reset and run correctly with a power cycle- again, sounds normal- you just somehow invoked this stalled motor safety. That's just how the firmware works to attempt to protect the motor and drive circuit.

You may not have been aware of this feature and it might be more sensitive to voltage or track current problems in certain conditions that kick the safety in.

I had this problem with the new Acela.  Before returning for repair:

1) Change transformer/power source. Strangely, replacing my ZW with the Lionel PH180 or MTH Z1000 solved the problem.

2) Ensure minimal resistance between power source and track. Temporarily add wires between power and track.

3) Reset Procedures – If the engines fail to respond to commands (e.g., cab light blinking because its software “thinks” there is a motor binding issue), try to reset the engines. Here are two reset options:

          Reset option #1 when continuous one-blink error code occurs: (Idea thanks to @MineRun) This “unbinds” the motors to the satisfaction of the engine software

  • Hit reset (“R” with octagon around it) to turn off the blinking cab light,
  • Press down the 'boost/brake' wheel to reverse the direction,
  • Turn the speed wheel clockwise to back the engine up ever so slightly
  • Reverse direction again
  • Turn speed wheel again to move forward

          Reset option #2 for general reset:

  • With power on track, press the “R” with the octagon around it. The engine should respond with a short whistle.
  • Turn off power to track
  • Turn off command base power to stop TMCC/Legacy radio frequency from reaching the track
  • Wait about 30 seconds.
  • Restore command base power
  • Restore track power.
  • Turn speed wheel to move forward
Last edited by Bruce Brown

I have the NYC version of this locomotive. I learned that it is sensitive to low track voltage and couple that with more than 4-5 cars it will stall and throw a code.

My solution - added another power drop to the back-end of my layout (I have a small 5x9 with one Powerhouse 180 and lock-on) and I only run it with 2-3 cars. These are geared pretty low and are not designed to handle more than 3-4 cars for an extended length of time.

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