I recently committed a big error by leaving my loco in its plastic case on a table in the afternoon So. Cal. sun. The result was a melt down of the tender shell and the cab on the loco shell . After removing the tender shell, I found no physical evidence of damage to the PC board or the components. However, when I put it on the main line and then my programming track, I could not access the loco with my Digitrax Zephyr system. When I tried to read the loco address the response wwas dnd, no decoder detected. I checked the Bachmann online Parts catalog for the 4-8-2 Heavy Mountan and found that the PC Board with decoder was not in stock. I called the Bachmann Service Dept. and they verified that this part was not available and did not know if it would come back in stock. Also, no Spectrum Heavy Mountains were available if the loco was returned for service. I did order a replacement loco and tender shell to repair the cosmetic damage done by the afternoon sun tan. With the tender shell removed, it appears that the DCC decoder is hard wired to the PC board. Can this decoder be removed and a new one wired using the existing wires? If so, has anyone done this and what decoder? Thanks for any assistance you can provide. This loco was the pride of my fleet George
There many hard wired decoders available for replacement. I have used these, Digitrax DZ123, DZ125 or TCS M1. Use the Bachmann Heavy Mountain drawing to attach the wires to the light board. http://www.bachmanntrains.com/home-usa/references_2010.php Hope this helps. Harold
Yes, he decoder can be removed. Pay close attention to numbers where wires are attached to the PC board. Bachmann does not use wire colors other than black or varnish coated wire, note that wire closer to loco is number 8 which will be a red wire on replacement decoder. Starting from there the wires are 1 to 7 with 7 being closest to rear light. If you removed the tender shell and disconnect the connector from loco check that it is orientated properly. I don't think that heat would damage the decoder just thinking of things that cam cause your problem. It may well be that heat damaged the decoder. Doug
A long shot... I've had problems in the past with my Digitrax programmer giving me a 'decoder not detected' error when I knew the decoder was there and still good. Here is what I did: Turn the locomotive on its back. Use a q-tip and alcohol and clean the wheels where they make contact with the rail. Clean the programming track. Put the loco back on the programming track. Try to read the decoder again. You may find you have to 'jiggle' the locomotive gently back and forth a few times. I have used this method and have found the decoder on the Digitrax every time. Worth a shot ?
Thanks all! I'm waiting for the new tender shell to arrive so that I can secure the current board w/decoder to the frame and make sure the tender wheels are providing good electrical contact. Then I'll recheck both on the "main" and the programming check to verify the status of the decoder as you've pointed out. If "dnd" again, then I know how to replace it, thanks to your responses. George
