MTH E6 Smoke Unit Runs Amok!

Well, it sounds like the smoke FET has shorted as an initial guess.

If you don't use smoke at all, the simple solution is to unplug the smoke unit connector from the PCB, problem solved.

gunrunnerjohn posted:

Well, it sounds like the smoke FET has shorted as an initial guess.

If you don't use smoke at all, the simple solution is to unplug the smoke unit connector from the PCB, problem solved.

Thank you, GR!  I thought I'd somehow gummed up the works.  Since I intend to convert the unit(s) to Kadees, this gives me the impetus to open her up earlier than anticipated.

Since I have your expert attention, let me ask one other semi-related question regarding "unplugging":

I made my first MTH-Kadee locomotive conversion recently on my U30C but with unintended results.  I unsoldered the electrical connections at the electro-couplers, opened her up gingerly, traced the wiring back to the plugs, unplugged them, carefully (very, very carefully) removed the then superfluous wiring, buttoned her back up and installed the Kadees.  However, when I rerailed the unit and powered her up, nothing happened... nothing, nada, zip.  The handheld unit refused to recognize the unit which had been "added" weeks earlier.  I made all the standard checks such as wheel alignment, contact, and operation of another locomotive; all to no avail.  So much for what I thought was a good job!  Pride cometh before the fall.

Therefore, based on this experience, I've been reluctant to revisit the matter without some sage advice and suggestions.  This also makes me gun shy regarding the E6 project.  Could unplugging (breaking) the electro-coupler circuit(s) have created the problem?

Nothing is so easy as the job you imagine someone else doing!

The 'min' setting and rheostat you mentioned above was what caught my attention. Just a thought here.

By 'menu system' do you mean DCS? If so you have to turn the smoke 'off' with DCS. The rheostat on the engine only applies to conventional operation.

Of course it could also be the bad part that GRJ mentioned as well, I will leave the electronics to GRJ and the others that know what they are doing.

First off, I doubt that simply removing the electrocouplers caused your issue, I've installed a number of PS/2 boards without electrocouplers, didn't affect them a bit.

On the smoke, did you try toggling the smoke off under DCS?  I assumed you did, but perhaps that was an invalid assumption.  As far as unplugging the smoke, it's the 4-pin connector, it handles just the smoke and smoke motor, so it's an easy disconnect.

GR & RTR,

I use DCS and the menu for smoke presents only three choices: "MIN  MED MAX"  There is no "OFF" prOFFered...

EUREKA!  (DUH!)  I just found the "button" on the handheld, No. 1.  I've become so entangled in all the Menu hogwash that I've forgotten that there are simple answers.  I liked the little switch on the underside of the frame that read: "Smoke On-Off".  What was wrong with that?  Too complicated for Gen X?

Apologies for leading you on this not-very-wild goose chase,

Chagrined

The pot should have worked for conventional, my guess is perhaps there's a wire off the pot?  A conventional reset may restore that function, did you try that?  Five bells and the whistle spaced at 1/2 second intervals.  You'll get two toots if it's successful.

GR, I never tried it in "conventional" since I just have a brick hooked up to that "layout".  The "Smoke" button has worked to kill the smoke and also has made me feel REALLY STUPID.

A retest of the U30C reveals yet another mental defect on my part.  It's not a lack of recognition, it's a lack of a good circuit - both in my brain and in the locomotive.  My memory has failed me and I had forgotten that there's simply a dead short, the brick "pops" the moment it's plugged in.  I rechecked everything, including the clearance between the Kadee "brake hoses" and the 3rd rail.  A surgery and a couple of weeks have intervened between my modifications and my present embarrassment, so, I'll just have to take the engine apart, again, and report.