I have a DCC BLI K-4 Pacific that has had a problem stalling out going over insulated turnouts since the day I bought it. I have determined that the problem is it is not receiving power from the left side driver wheels, only the tender wheels, and this results in a stall when these pass over an insulated frog. I thought about sending it back to the factory but had read the stories about the long wait and it seemed like it might be as simple as a loose wire so I elected to see if I could fix it myself. I am usually reluctant to open up things with electrical components, especially expensive ones so I put off doing that until today.
I first removed the pilot and trailing wheels to get those out of the way. Next I removed the chassis which holds the driver wheels in place but I could lift those just a short distance because they remained attached to the driver rods which seem like a delicate assembly, not recommended for someone with 58 year old eyes and more that the usual complement of thumbs. Next step was to remove the boiler which was fairly simple. I was hoping I'd see a loose wire that needed to be screwed or soldered back into place but no such luck. What I can see at this point is four wires running from the tender to a plug in the circuit board behind the motor. There is another small wire which seems to run from the area of the circuit board to the back of the motor and is soldered solidly in place. There is another circuit board in front which I am guessing controls the head light. Nothing appears obviously out of place. I tried to see if the motor could be lifted easily so I could see underneath but if it is meant to be lifted out, it is going to require a little force to accomplish that.
I realized at this point I have already invoked the Peter Principle, rising to my level of incompetence by even going this far. I am fairly confident I can reassemble what I have taken apart so far but I'm afraid I might cause some serious damage if I go any further without some guidance. If anyone who has had more experience working on the insides of these locomotives has any advice, I would appreciate it. My thought is to disconnect the driver wheels from the rods allowing me to see what those are hiding, but were getting into parts that seem best left to someone with a jeweler's touch and eyes and that sure ain't me.
Hi,
If all else fails try e-mailing them your question. They are very good about replying.
Broadway Limited Imports Service Dept <service@broadway-limited.com>
Their phone # is 386 673 8900 (not a toll free number)
You've gotten a lot further that I would have. I don't try unless the engine isn't worth much as putting things back together is my big problem..
Good Luck,
Bob
Don't Ever Give Up
It could be a broken wire in the tether, a broken pin-wire connection in the plug, a bad solder anywhere, a defective board, dirty pickups along one or both sides. Sometimes reseating the plug into its receptable works. Recently I had an engine go intermittent on me, so I removed the tether, inserted it, tried it, no go, repeated, and now the thing runs well. I suspect that corrosion or something will have me doing this on all engines over time.
Contact cleaner might be the trick.
-Crandell
Two wires in the connector go to each respective side of the motor, two are for the headlight, and two go to each respective side of the frame, and in turn to the drivers on that side. One of the connections to the frame is almost underneath the motor. I don't recal where the other is.
I'd take a multi-meter on continuity (ohms), and test each pin on the connetor to verify the above.
Do this so you don't spend time tracing the working side drivers, and so you know where all the pins go.
See if you can locate the screws that hold the wires from the connector to the frame sections and check the continuity between the screw and the connector pin, and from the screw to the driver tires.
I doubt the problem is the driver tires, however, my BLI M1s had a thick black "overspray" for lack of a better word, that was hindering electrical contact. I used a dremel wire brush to remove it and it improved quite a bit. My K4s run like watches, but I have had one apart to see how it worked.
I agree it could also be the tether. It seems there have been some problems either seating them, or having flash in the holes. BLI will definately send you one of those, if you find it's not conducting.
While you're at it, take off the tender shell, and make sure the connector is seated on the circuit board.
Let us know how it's going.
All good suggestions. At least it gives me several things to try and hopefully one of them will do the trick. I noticed the black "overspray" on the wheels too and thought it was gunk build up but since it was on the good wheels too, I didn't think it was the source of the problem. I'll add cleaning the wheels to the tasks to be performed. Thanks everybody.
I''ve had a chance to try out a few suggestions and I think I at this point, I can rule out several things. I don't think it can be a problem with the tether or the plug because as long as the tender wheels are on powered rail and not the insulated frogs, the engine runs fine. I confirmed this by placing the tender only on the rails. The small circuit board behind the motor has 6 small terminals at each end. My voltage meter indicates that receiving power from the tender only, I am getting power to these terminals both on the front and back of the circuit board. It also appears that the wire on the back of the motor is attached to the right side of the loco which is the good side. I'm guessing that the connection to the left side is somewhere under the motor.
I put the loco only on the rails and I get no power at all that way. However, I did determine that if I ran a jumper wire from the left hand rail to the left terminal post on the rear circuit board, power kicked into the loco and tender because the sound came on as soon as I did this. I also removed the chassis again over the driver wheels and carefully lifted the weel assembly out of its sockets and it appears there is no wire running from the drivers to the motors. There are six brass fittings on each end of the three axles and these must be oriented very precisely in order for the assembly to sit properly in the sockets so the chassis can be reattached. I am going to take an educated guess and say these brass fittings are the electrical contact to the frame and there should be a contact between the frame and the underside of the motor, but because I can't lift the motor, I can't confirm that. I am going to make another educated guess and say this is likely where the break in the circuit is. At this point I would like to lift the motor and see if I can tell where the break is. Unfortunately, the motor seems securely fastened to the frame and I don't see any screws which are holding it in place. Naturally I don't wont to force the motor out. If someone knows how to safely lift the motor out, it would be a big help at this point. For now, I'm going to put this aside and move on to some other projects and hope someone can provide some additional information.
There should be NO contact between the wheels on either side and the motor directly - this is a DCC no-no. The only place you should see continuity between the wheels and anything is the appropriate pin of the tether cable. The motor power comes forward only from the tender.
The little brass pieces are the bearings. If the drivers are sprung like the ones on my T-1, there should be a little spring in a pocked in teh frame above where this bearing slips in place. And then the bottom cover goes on.
--Randy
Modeling the Reading Railroad in the 1950's
Visit my web site at www.readingeastpenn.com for construction updates, DCC Info, and more.
rrinker There should be NO contact between the wheels on either side and the motor directly - this is a DCC no-no. The only place you should see continuity between the wheels and anything is the appropriate pin of the tether cable. The motor power comes forward only from the tender. The little brass pieces are the bearings. If the drivers are sprung like the ones on my T-1, there should be a little spring in a pocked in teh frame above where this bearing slips in place. And then the bottom cover goes on. --Randy
This does not seem to be true with my BLI 4-8-2. With that loco, I can tip either side of the tender off the rails and the loco will still draw power from the drivers. I can tip either the left or right drivers off the rails and the loco will still draw power from the tender. In fact I can lift the tender completely off the rails, and the loco will continue to draw power through the drivers only. It responds to commands with no tender wheels on the rails. The problem is that the 4-6-2 will only draw left side power from the tender and since it has a short tender with just two axels on each truck, the wheel base is less than the length of the insulated frogs on my Atlas turnouts. If it is going fast enough, it will slide through the frog and resume power pickup when the wheels reach the other side but even then, there is a noticeable hesitation. It seems to me with the design of these locos, the drivers on both sides must pick up power for them to work right.
This does give me an idea for a possible fix. The tender draws left side power from the front truck and right side power from the rear truck. Since it is also drawing right side power from the drivers, I could modify the tender so that both the front and rear will draw left side power. That way, one truck or the other will continue to draw power when the other truck is over the insulated frog. The driver base is longer than the frogs so it will always have at least one and probably two drivers in contact with a powered rail.
That's the way I see it...they are brass bearing inserts. I removed the driver assembly from my little P2K 0-6-0 once and found the same thing, and boy were they bears to get oriented and back into their slots!!!
The motor, as Randy says, must/can/ought only get power routed from the decoder directly. So, no other contact is wanted...or the magic smoke escapes from the decoder.
There should be power supplied by one or more driver axles to the decoder, though, not just the tender. So, somewhere there should be two wires coming from the driver axles and going to the decoder. There should be leaf wipers hung up against the drivers, nested near those brass bearings, and then wires feeding the decoder. The axles are insulated, to my knowledge, so that there can be no shorts through the axles.
IIRC, the axles on my T-1 were all metal and not a split design (like Athearna nd P2K diesel wheels) - the insulation was at the driver hub. What happened with my T-1 was that it picked up from both sides of the tender but only 1 side of the loco - I traced this to a poorly inserted plug on the circuit board in the tender - which happened to be that of the wire leading from the missing pickup side of the loco via the tether to the decoder. Simple fix and I ended up with a very large wheelbase for power pickup. I resisted taking the bottom plate off the loco chassis, as visions of messing up the driver quartering ran through my head. I did take the boiler shell off - I found the motor wasn't mounted straight with the shaft perfectly in parallel with the frame. The universal joints handled this, but since it was always loaded to one side, it caused a slight hitch in running at the lowest speeds. I loosened the motor screw and held the motor straight while retightening it - another simple fix that made a world of difference.
rrinker IIRC, the axles on my T-1 were all metal and not a split design (like Athearna nd P2K diesel wheels) - the insulation was at the driver hub. What happened with my T-1 was that it picked up from both sides of the tender but only 1 side of the loco - I traced this to a poorly inserted plug on the circuit board in the tender - which happened to be that of the wire leading from the missing pickup side of the loco via the tether to the decoder. Simple fix and I ended up with a very large wheelbase for power pickup. I resisted taking the bottom plate off the loco chassis, as visions of messing up the driver quartering ran through my head. I did take the boiler shell off - I found the motor wasn't mounted straight with the shaft perfectly in parallel with the frame. The universal joints handled this, but since it was always loaded to one side, it caused a slight hitch in running at the lowest speeds. I loosened the motor screw and held the motor straight while retightening it - another simple fix that made a world of difference. --Randy
Well, I'm a little slow, but I think I'm catching on. The power from the drivers must first be routed back to the tender, through the decoder, and back to the motor. Makes perfect sense now that I think about. Why would you want power going directly from the drivers to the motor. DUH!!! I guess my mind still works in DC mode.
I wish I had had the good sense not to remove the chassis because I did mess up the driver quartering and had a devil of a time trying to get the bearings and axles seated correctly in the slot. After struggling with it for over half an hour, during which time some colorful language was used, I managed to get them back in place. I put the chassis back on then put it back on the track and noticed that one of the rods had bent outward. Badly. I'm guessing the result of working the bearings and axles back into place. I thought I'd really messed it up badly, but amazingly, I was able to get it straightened out and it seems to be running OK again except for the original problem, which now I have a good idea where to look for the solution. In the tender.
Assuming the power is getting to the tender - there still could be a problem from the pickup to the connector inside the loco, but it will be in the boiler/cab, not in the frame. You should be able to remove the boiler and cab without taking the drivers out. But it's easier to get to the appropriate wires int he tender. If there's no power there, then you have to work back through the connector and possibly back into the loco.
rrinker Assuming the power is getting to the tender - there still could be a problem from the pickup to the connector inside the loco, but it will be in the boiler/cab, not in the frame. You should be able to remove the boiler and cab without taking the drivers out. But it's easier to get to the appropriate wires int he tender. If there's no power there, then you have to work back through the connector and possibly back into the loco. --Randy
I'll used my voltage meter to figure out if the power is getting back to the tender. The boiler has been off since I opened the loco up so if that's where the problem is, it should be easy to figure out. At least now I think I'm on the right track instead of just groping in the dark.
EUREKA!!! I found it.
I've been working another problem the last couple days in between watching football and just got back to debugging the problem with the Pacific this afternon. I used the voltage meter to determine that power was not being passed from the left side driver back to the decoder in the tender. There is a small circuit board behind the motor with 6 terminals on it with corresponding wires leading to and from the tender. I disconnected the tender and put the loco on the track by itself. I was able to determine that track power was reaching the right most terminal from the drivers, but the corresponding terminal on the left side was not receiving power. I reconnected the tender but insulated the left tender wheels from the track and then ran a jumper wire from the left side rail to the dead terminal on the circuit board. The locos sound system kicked in. This confirmed to me that there was a broken connection from the left side drivers to the circuit board.
I traced the wire from the outside left terminal to another smaller circuit board in front of the motor. I had assumed that was the one that controlled the headlight but I saw that there were 4 wires leading to that board and I knew only 2 would be needed for the headlight. There was a small screw holding the board in place so I unscrewed it and lifted it. Below it was a small piece which I guessed was some sort of insulator. I lift that up an was surprised to see there were 2 screw holes. 1 screw and 2 screw holes does not compute. Even someone as electronically challenged as me could figure out that wasn't right. Luckily, I was able to find a suitable substitute screw in my spare parts box. After getting both circuit boards screwed back into place, I put the loco and tender back on the track and once again, the sound effects kicked in. When I lifted the tender wheels off the track, the sound kept coming, receiving power only from the drivers. I knew I had fixed the problem. I then ran the loco, with no boiler, pilot, or trailing wheels on, just a funny looking 0-6-0. It passed over the insulated frogs without any hesitation. Now if I can just piece the loose parts back together, I'll have a really nice loco.
It was a good day today. I fixed several problems with my mainline track as well as some problems I'd had with my new 20th Century Limited and could make a complete tour of the layout with my new train, something I hadn't been able to do since I put it on the track New Year's Day. I needed a good day. I haven't had many lately. It seemed like every day a new problem would pop up and I was getting more than a little discouraged. I finally feel I'm close to getting the layout in good working order and I can go back to working on completing the scenery.
Congratulations, John!! You won't forget this.