30-1601-1 Rail King FEF, dead

I doubt you can hear the caps charging.  For those engines, look at the drawbar and make sure no exposed pins on the bottom, or the wiring harness that runs from the drawbar to the engine board does not have damage from metal rubbing, or the exposed pins have touched metal on the trail truck or metal bar.  G

GGG posted:

I doubt you can hear the caps charging.  For those engines, look at the drawbar and make sure no exposed pins on the bottom, or the wiring harness that runs from the drawbar to the engine board does not have damage from metal rubbing, or the exposed pins have touched metal on the trail truck or metal bar.  G

Something is making a whining sound I can hear when it's powered. I figured it might be the caps (I've heard some whine, just not on a MTH board), but something is whining when first powered up.

I checked the wiring harness for shorts to the drawbar and found nothing. All factory insulation is in place. I'll double check again just to be sure. 

Looks like the culprit is a bent drawbar and the pins on the locomotive end touching the bottom of the cab. You can see where the pins scraped away paint on the bottom of the cab. Owner looks to have been pressing the drawbar in from the middle of the drawbar, instead of the end at the tender. This gave the drawbar a slight upward U shape in the middle. As the drawbar moves up and down it could hit the bottom of the cab and short to ground. Confirmed by moving the drawbar up and checking for continuity with a multimeter. Straightened the drawbar and it's now impossible for the pins on the locomotive end to touch the bottom of the cab when the locomotive and tender are connected. Gonna cost the guy a board set unfortunately. 

MTH has a cover for that, and I think it was included in later versions.  Became issue on some BigBoys and other articulated engines with those drawbars. G

I got two smoked RK Big Boys in for service before I found out what was taking them out.   I don't get how they miss this obvious design flaw before it leaves the factory.

Had the same issues with my 2003 K-line Allegheny, fortunately it didn't take any boards out, just stop running, usually on a curve.

A relatively thick rubber sticky pad fixed it.

GGG posted:

MTH has a cover for that, and I think it was included in later versions.  Became issue on some BigBoys and other articulated engines with those drawbars. G

Got a part number for the part? If not I'll fab something out of sheet styrene to cover it.

gunrunnerjohn posted:

I got two smoked RK Big Boys in for service before I found out what was taking them out.   I don't get how they miss this obvious design flaw before it leaves the factory.

Do you remember if both the boiler board and tender board were taken out or just one? 

At this point I think it would be a waste of time to put the boards on a tester to see which one is dead. 

In both of the RK BB's, it was the tender board that bit the dust.  I then started trimming the pins flat and putting a couple of coats of liquid tape on them, problem solved.

So the expensive board bit it. Well I'll have the boiler board tested to see if it's ok before ordering both boards.

You had me at "hearing the capacitors charging".

aussteve posted:

You had me at "hearing the capacitors charging".

You mean everyone doesn't hear these things?

https://en.m.wikipedia.org/wik..._noise_and_vibration

Clearly, I'd test both boards before moving on, my experience is only a sample of one.  Of note, I always test the two boards if I have this kind of failure.

gunrunnerjohn posted:

Clearly, I'd test both boards before moving on, my experience is only a sample of one.  Of note, I always test the two boards if I have this kind of failure.

I was planning on pulling both boards and bringing them to the LHS (which has a board tester) and seeing which one died. No sense in replacing both boards if only one is dead.

Ran the boards on the tester. Tender and boiler boards nuked, along with the tach reader. Replaced everything, loaded new chain/sound files, and away it went.

I made a cover for the exposed metal pins out of some 90° angle plastic. Should prevent the problem from reoccurring.