Crazy PS-3 Loco Issue

Try a factory reset. If you can look inside, look for the motor wires connections to make sure they aren't rubbing on the motor.

Basil posted:

I have a year old PS-3 diesel unit that was operating on my clubs Lionel Legacy layout just fine.  Suddenly, it only goes in reverse at full speed on the layout.  I brought it home, reset it through my DCS system, brought it back to the club and the problem persists.  As soon as I apply power to the track it takes off, full speed, in reverse.  Nothing has changed on our layout, no cable switching or electrical monkeying around.  Any thoughts?

Sound to me like a faulty tach reader although I have not worked on an MTH in a while I seem to remember a bad tach causing an issue like this.

When you reset it on your home DCS system   Did it work properly?   If it didnt its probably a bad tach reader.   If it did try doing a conventional reset

Bad tach does not make it go in reverse like that.  But the question is good.  Does it work right with your DCS.  Does it work in conventional on your track?

If engine always runs in reverse at full speed even after conventional and DCS resets, could be a shorted motor fet.  G

Thanks for the replies, Gents!  It functioned normally after a factory reset on my test track.  I have not reset it again since bringing it home Wednesday, but will get to it this evening.  The last time, though, it started in idle and responded appropriately to all commands I gave it through the remote.

Basil

I forgot to add, this is not the only engine this is occurring with.  I have another PS-3 diesel engine that did the same.  I didn't bring it to the club to test it on Wednesday after its factory reset. However, after a factory reset at home, it too functioned as normal on the test track.  I won't get it back to the club until next Wednesday, though.

I got the GP 40 on my test track and it operated perfectly in PS3.  I switched it to conventional via the remote and it instantly went in reverse.  Does this mean it's merely locked in reverse in conventional?  Also, I don't know how to do a "conventional reset" as the remote only gives me "Feature" and "Factory".

Conventional reset No dcs signal just bell and whistle buttons.

One whistle followed by 5 bell presses

Engineer-Joe posted:

Conventional reset No dcs signal just bell and whistle buttons.

One whistle followed by 5 bell presses

2 horn sounds after the above means the reset took. If not you have to try again until you get the proper 1/2 second timing.

That's the equivalent of a "feature" reset from the remote, correct?  I'll give that a go first.  Right now my Z4000 is stowed away. I'm powering my test track with a Lionel 80 watt. 

Similar but not exactly the same as a feature reset. 

May not work with the CW-80, bad wave form for PS engines.  G

I admit I'm being lazy in that I haven't taken out the 4k yet, but I did do a feature reset with the remote and the CW-80. When I switched the loco over to conventional it went forward. I take that as a postive sign. Now I'll do the same to the other loco that was doing this and test them both on Wednesday at the club. Fingers crossed!

Sometimes using a Lionel cw80 will scramble an engine like this I've read.

A conventional reset is done with no signal present. So you can't use the remote. 

I love to use Stans video to show how it's done. It's easiest with the Z4000 for me.

My brand new at the time, ps3  Sd80mac got locked in reverse by dcs in a lashup. It was fixed with a conventional reset like Stans video. I bought another engine back then and that one needed a reset right out of the box.

Perhaps I should pull out the Z4k. Everything has been good so far with the CW-80, but the right equipment for the job is certainly the most prudent course.

To close the loop, you guys were correct on the conventional reset.  Worked like a charm! Both locos that got stuck in instant reverse were completely cured of whatever ailed them with a conventional reset and both work as they should. Thank you for your help, I really appreciate it!