mydartswinger
Member
Good evening all,
I've been working on a couple of locomotives for a friend over the last few days. Unfortunately, I'm unable to fix them. I can't figure out what's wrong with them (well, I at least have an idea on one of them, but have no way or don't know of a way to test it).
The first locomotive is an Ho scale Bachmann DCC equipped UP DD40 (road # 6900). The issue with it initially was that it wasn't running. It was originally thought to be bent pickups, but I believe I've ruled that out. I put it on my track to test run it. It runs on straight DC and was running on DCC address 03. I attempted to program the address using page mode and the loco keys on my Zephyr to do so. I kept getting an open circuit error, though it would still run on address 03. Just for good measure, I checked and adjusted the pickups a bit to find no change. The Bachmann manual combined with the Digitrax manuals left much to be desired for troubleshooting guides. I thought that maybe the Bachmann decoders could be like the MTH decoders in that they prefer to be programmed in Ops mode on the mainline. I removed the other locomotives from the main line and attempted to change the address. First using the loco buttons, then by setting CV29 per the Digitrax mobile decoder manual and CV17 & CV18 for the address. Now the loco will only run on straight DC power and won't respond on DCC with any address (right back where it was when I tested the locomotive at our club's layout). I do have a concern that the board may be burnt at the decoder plug, as there are black marks between 2 of the solder joints above the decoder socket on top of the light board. These won't rub off, and feel/look almost like they're embedded into the glue on the board. I'm also suspecting a bad decoder, but I don't have a Bachmann compatible decoder (jumper type plug) to test with. All I have are Digitrax decoders (slot type plug). The locomotive did come with a "dummy" plug. What could be wrong here?
The second locomotive is an HO scale Bachmann Limited Edition Norfolk and Western Class J (one of the older ones). The problem with this is that it has a horrible shimmy while running. The nose of the engine moves left to right while going down a straight track. The wheels are in gauge and the axles and driving rods do not appear to be bent. However, the axles slide quite a bit (about 1/8" to 1/4" to either side). I attempted a temporary test fix of applying strips of masking tape between the wheels and the frame. I did this just to test that it is in fact the problem. If it was, I could feasibly devise a way of fixing it in a more appropriate manner. However, this had no affect on the wobble. Other than that, the engine is in good shape and runs well. What could the issue be here?
Thanks in advance for any advice you may be able to provide.
Shannon
I've been working on a couple of locomotives for a friend over the last few days. Unfortunately, I'm unable to fix them. I can't figure out what's wrong with them (well, I at least have an idea on one of them, but have no way or don't know of a way to test it).
The first locomotive is an Ho scale Bachmann DCC equipped UP DD40 (road # 6900). The issue with it initially was that it wasn't running. It was originally thought to be bent pickups, but I believe I've ruled that out. I put it on my track to test run it. It runs on straight DC and was running on DCC address 03. I attempted to program the address using page mode and the loco keys on my Zephyr to do so. I kept getting an open circuit error, though it would still run on address 03. Just for good measure, I checked and adjusted the pickups a bit to find no change. The Bachmann manual combined with the Digitrax manuals left much to be desired for troubleshooting guides. I thought that maybe the Bachmann decoders could be like the MTH decoders in that they prefer to be programmed in Ops mode on the mainline. I removed the other locomotives from the main line and attempted to change the address. First using the loco buttons, then by setting CV29 per the Digitrax mobile decoder manual and CV17 & CV18 for the address. Now the loco will only run on straight DC power and won't respond on DCC with any address (right back where it was when I tested the locomotive at our club's layout). I do have a concern that the board may be burnt at the decoder plug, as there are black marks between 2 of the solder joints above the decoder socket on top of the light board. These won't rub off, and feel/look almost like they're embedded into the glue on the board. I'm also suspecting a bad decoder, but I don't have a Bachmann compatible decoder (jumper type plug) to test with. All I have are Digitrax decoders (slot type plug). The locomotive did come with a "dummy" plug. What could be wrong here?
The second locomotive is an HO scale Bachmann Limited Edition Norfolk and Western Class J (one of the older ones). The problem with this is that it has a horrible shimmy while running. The nose of the engine moves left to right while going down a straight track. The wheels are in gauge and the axles and driving rods do not appear to be bent. However, the axles slide quite a bit (about 1/8" to 1/4" to either side). I attempted a temporary test fix of applying strips of masking tape between the wheels and the frame. I did this just to test that it is in fact the problem. If it was, I could feasibly devise a way of fixing it in a more appropriate manner. However, this had no affect on the wobble. Other than that, the engine is in good shape and runs well. What could the issue be here?
Thanks in advance for any advice you may be able to provide.
Shannon
Last edited by a moderator:
