Another Bachmann K4 bites the dust

[Rich_S]

Not sure if anyone else has run into this issue? But only after a few weeks of use, my Bachmann K4 1361 is somewhat dead in the water. It will sit and hiss and run the air compressor all day long, but as soon as you try to move forward just a foot or two, dead, lights out. Put slight pressure on the tender and it comes back alive for another few inches to a couple of feet then dead again. The track is clean and from what I can see the wheels on the locomotive look clean and shiny. All my other locomotives run just fine, so it's not a DCC issue. I even tried using straight DC and same issue. Tried resetting CV8 to 8 for a factory reset and still no joy. The way it acts, it's almost like a contact issue, but from what I can see the wipers are making contact with the wheel pickups on the tender. I guess since it's only a few weeks old, off to Bachmann it goes, very disappointing 

[draskouasshat]

Try placing some temporary weight on the tender and let it run. Might just need to add some weight to help the contacts a bit. See if this helps before you send it back. Do these decoders have keep alive capacitors in them? That would explain the short runs before stopping.

Adam Draskovich

[peteski]

You could do some additional very simple troubleshooting in DCC.  I'm assuming that since you reset the decoder you are using short address 3.

When on programming track, can you read out the decoder's CV values (like CV29 or the loco's addresses (short and long)?

Can you turn the headlights on and off?
When on, do they respond to the loco's direction setting (on the throttle)?
Can you activate sound functions like bell and whistle?

Try the above with and without extra weight or pressure on the tender/

[Rich_S]

You could do some additional very simple troubleshooting in DCC.  I'm assuming that since you reset the decoder you are using short address 3.

When on programming track, can you read out the decoder's CV values (like CV29 or the loco's addresses (short and long)?

Can you turn the headlights on and off?
When on, do they respond to the loco's direction setting (on the throttle)?
Can you activate sound functions like bell and whistle?

Try the above with and without extra weight or pressure on the tender/

Peteski,  I reset CV8 to a value of 8 just to see if there was a decoder issue, but that did not help. I've reset CV29 to 36 to enable long address and Analog modes and I've set the decoder address to 1361. I do not think the problem is a DCC issue, I think the problem is a contact issue. When the locomotive stops, the head light goes out and the sound quits. When I touch the tender, the lights come back on and the sound resumes. When contact resumes, yes I can control the headlight and all sound functions.  I've even tested the locomotive on a DC test track and have the same issue, it's almost like it's loosing contact, causing a momentary dead spot?

[Rich_S]

As a follow up, it's definitely going back now. I tried to run the locomotive this morning, it moved about a foot and then it began to smoke. When I picked the locomotive up, one axle on the front tender truck fell out and the other axle was melted to the tender. Something shorted in this locomotive as all other locomotives on my layout are running OK.

 

[Chris333]

DCC is fun! 

[mmagliaro]

EDIT:
Nevermind.  In light of the "smoking and melting"... my earlier thought on cleaning and such are irrelevant.

[basementcalling]

Smoking locomotives is not healthy, and probably illegal in all 50 states.

[Rich_S]

Smoking locomotives is not healthy, and probably illegal in all 50 states.

Oh no, now you tell me     

On a serious note, this is a shame as this locomotive was a great running, looking and sounding locomotive, that is just before it went up in smoke. I realize there are always manufacturing issues, could have been something with the Sound Decoder, who knows but something definitely caused a direct short to melt that axle on the tender? This is the second Bachmann locomotive I've had problems with, my H16-44 for some unknown reason will let the smoke out of it's decoder every 6 months. It's gotten to the point that I no longer put a decoder into that locomotive, I'm tired of sending decoders back to the manufacture. The crazy part, the H16-44 runs just fine on DC even though it's a bit of a growler, will run great on DCC for about 6 months and then for no apparent reason, will let the smoke out of the decoder. The H16-44 was a hard wire and I used heat shrink on all connections and Kapton tape on the motor terminals. The only thing I can think of is it has to be an issue in the motor that effects DCC, but not DC if that's possible?

 

[up1950s]

Kind of sounds to me that the tender wheel of melted fame was put in backwards . Did a wheel pop out ? Can you visually identify the insulated side of each wheel set by just eye balling ? The errant wheel might have not be making contact do to who knows what , not uncommon . Once the loco was broken in , contact was made , and it turned into a intermittent short , then dead short , then glow plug .

This is why ammeters , voltmeters , and DC appeal to me so much . Not that I haven't burnt stuff up myself .

[Chris333]

They are probably like previous Bachmann tender trucks, and like Kato. Both sides are insulated with a plastic axle "muff"

[Lemosteam]

Confirmed @Chris333 The Bachmann tender axles are dual insulated and can be installed either direction.

[JMaurer1]

Smoking locomotives is not healthy, and probably illegal in all 50 states.

I thought that all steam locomotives smoked?

[peteski]

I don't own this model so I'm making some assumptions. I assume that the tender has all-wheel pickup.

This sounds to me like the loco was allowed to sit at some location on the track (probably a turnout or auto-reverser) where the same side rails were at opposite polarity.  The differing polarities were either between wheels on the same truck or between the front and rear truck. If the resistance of the electric pickups in the tender was high enough not to trip the throttle's (DC) or command station's (DCC) breaker (but low enough for higher current to pass through the tender) then the high current caused the electrical path of the short in the tender to heat up and melt.  At this point the damage is severe enough where it affect electric pickup. At least this is what I think has happened.

[Dave V]

Achievement unlocked! 

Secret smoke unit.