Stewart Lighting Problem - Model Railroader Magazine

 Are they directional on DC, and if so, do they work int he right direction? Or are they backwards? If they are backwards then the LEDs were installed backwards, but re=bending them to flip them over will probably snap the leads. If they work the way they should in DC, the the fault it probably on the circuit board itself. You should be able to get replacement parts from Bowser, possibly under warranty if you bought it new/.

 I'd start with LED polarity - the headlight LED is easy to get out, it's held by a plastic clip that pulls right off.  LEDs typically have a flat spot to indicate polarity - compare to the good oen and see if it's orietned the right way. If they don't match, you've found the problem.  Here's a picture of how I bent new LEDs, I used Miniatronics Yelo-Glo 3mm:

The little black thing is the clip[ for the front light. The one on the right is the rear light. The cab interior has 2 small tabs on the cab sides and it pops right out. With some needlenose pliers to hold the leads, bend them to match the stock LEDs and they will make perfect contact witht he copper tabs.

 If the problem instead lies with the circuit board, no amount of replacing LEDs will make it work. Make ure the component orientation on your board looks like this:

The only thing that can really be wrong is the round black bridge rectifier. In the picture, the cab is to the right.The + marking should be on the upper left like shown. If not - you found the problem. If it's the same, then I'm betting ont he LEDs being backwards. The browish things on either side of the rectifier and DCC socket are the resistors, yours will look differe,t I repalced mine with a higher value because the lights were just plain too bright.

 Hard wiring a decoder in this loco would be easy, since all the wires follow NMRA color code, there are red on the right rail pickup, black on the left, and the motor wires are gray and orange. If you want to stick with TCS I'd use an MC2 as it is small enough to tape to the top of the motor to keep it out of the way once the circuit board is removed.

                         --Randy