Hello
Recently I was runing trains and my NW2 stopped dead on a switch, turns out the switch had a dead section, fixed that. Worse was the NW2 was only picking up track current from the front truck. Power to the back truck to turn the wheels was not affected. I pulled the nose off expecting to see a burned out wire which happened before in a bad derailment and I fixed it but nothing that obvious.
I pulled the offending motor block off to have a better look, connected the 2 plugs together applied power to the pick up shoes and it worked. Hmmmm There is a white wire that goes from the back circuit board nearest the cab to the front board which got scorched during the big derailment. The wire not the board. I’m starting to think this damaged wire may be the fault but the engine was operating as it should up until now. I tried jumping the wire from board to board but nothing happened?
I might try soldering a new wire to replace that charred one but I’m not the best at soldering.
Any ideas before I proceed as to why I’m not getting juice from that motor blocks pickup?
Thanks
Todd
Todd,
The same thing happened to my NW2. My problem was the control board. Call USA parts dept., costs about 12-15 bucks if I remember correctly. Takes about 1/2 to fix. If I can fix it, anybody can !
You might want to examine the gears on the axles, they’re notorious for splitting. I replaced all four at the same time, better safe than sorry.
All in all, the NW2 has given me hundreds of hours of use, so the repairs were for the most part, a periodic overhaul.
(http://www.elmassian.com/images/stories/motivepower/USAT/nw2/nw2_opened.jpg)
Does yours look like this opened? Now, whenever you stop or derail on a switch under track power, the situation exists that you have a short through the pickup wires. This is because one set of wheels on a truck can be getting the wrong polarity. Imagine your loco has derailed on a switch, and the rear truck is fine, but the front truck engineers side has come into contact with the wrong rail. Now you have a dead short from the front truck to the back truck, the wires for power pickup. Normally something melts if left long enough. This is always a danger in a derailment especially on a switch. The good news is that usually this does not damage the “innards” of your circuit boards, just the wires leading into them, although sometimes the front truck pickups are paralleled with the rear truck pickups via traces on the main board. Usually visual inspection will reveal where the problem is. Why I wrote all of this is that fixing the wire/trace may be all that is necessary (and not derailing and having a short circuit again ha ha). Regards, Greg
When you have a USA Trains locomotive open, inspect any wiring soldered to the main circuit board. I have found more frayed wires hanging on by a thread. After repairing them, I usually add hot glue to the wires at the board to provide stress relief and keep the wires from fraying. I don’t know why USA Trains uses 2-wire connector sets for the motor and track power wires at the circuit board. It would seem easier to install a header on the board and use slip-on connectors. That would also eliminate the frayed wires problem.
(http://ovgrs.editme.com/files/PnPFA1/PCB02.JPG)
I did that with the door mounted circuit board in my Aristo-Craft FA-1 as the wires to the tended to fray.
Paul Norton said:
When you have a USA Trains locomotive open, inspect any wiring soldered to the main circuit board. I have found more frayed wires hanging on by a thread. After repairing them, I usually add hot glue to the wires at the board to provide stress relief and keep the wires from fraying. I don’t know why USA Trains uses 2-wire connector sets for the motor and track power wires at the circuit board. It would seem easier to install a header on the board and use slip-on connectors. That would also eliminate the frayed wires problem.(http://ovgrs.editme.com/files/PnPFA1/PCB02.JPG)
I did that with the door mounted circuit board in my Aristo-Craft FA-1 as the wires to the tended to fray.
Welp I have found no frayed wires in any of my loco’s Must be a battery thing. NW2 is a great loco and very well built as is all USA Trains. Nick
I have never found a frayed wire either, but I guess if I did I could repair it. I only own about about 30 USAT locos though, so maybe my experience is not enough.
In any case, I’ll look more closely when I pull one apart.
Back to the subject of the thread, a picture of the damaged area would be great, or point it out on my picture.
Regards, Greg
Well bad news now I started investigating after reading the suggestions posted here and I couldn’t really find anything glaringly obvious. I pulled out my multi meter and went to test the volts from the bad truck to try and see where the juice ends and then tested the good truck to see what I should be getting for a reading and guess what NOTHING? So now both trucks are not working. I then replaced a suspect wire from the last time this happened since it looked like it was hanging on by a thread but it didn’t help. The wire is a white one from the front board to the one nearest the cab.
I don’t see anything burned, melted or scorched. Tomorrow I will do some more investigating.
Thanks
Todd
I think perhaps Paul is referring to a connection that isn’t fully tinned resulting in breakage or fraying at the circuit board? Just a suggestion Todd… have you applied fused power to the pick up shoes and just went through the wires one at a time with a very light wiggle/tug/pull. This is an accepted practice by many auto manufactures …know as the “wiggle test”. When I built my F-40 I used a USA Geep 9 as the donor …I accidentally discovered very bad solder joints on the board . However I disturbed them during the disembowelment not to mention after several years of hard use with no inspection and very light/lazy maintenance. DO NOT CUT THE BLUE WIRE!
(http://upload.wikimedia.org/wikipedia/commons/8/89/Bomba_atomowa.gif)
To debug, it sounds like you were doing this with track power or power somewhere.
that kind of testing usually results in the picture above.
I’d first put the meter on the ohms scale and figure out which wires from the trucks are the track pickups and which are the motor leads.
Greg
I was putting about 7-8 volts to the pickup shoes then using my meter probes to see if I could find out where the power stopped. I DID NOT CUT THE BLUE WIRE what movie is that from?
The latest update. I have power to the front truck which makes all 8 wheels move. Move alligator clips to the rear truck apply power and nothing BUT if I put a clip on the rear black wire side then the front truck red wire side it all works. It looks like I have a problem with the pickup on the red wired side of the rear truck. I did a wiggle test of each wire but nothing happened.
I also pulled out the board at the front, the one with the smokes etc… switches on it and I didn’t notice anything charred or loose?
Further investigation is needed.
GOOD NEWs the NW2 is back in service.
I traced the wire to the circuit board for the rear truck, I knew it was a issue with the red wire since I was able to jump around like I stated in the post before. I put power to the red wired side of the truck and touched my multi meter probe to the wire and soldered contact and BAM the wheels were turning. I tried it again and the wheels were turned again. This contact and wire looks perfect but NOT, so I applied some heat and resoldered it. So far so good. The engine is back together and we are heading out to hit the rails and move some freight around.
Thanks for all the help guys.
Todd
Great news. So basically it was a solder joint on the main board?
Could you point it out in reference to any picture posted?
Greg
Todd Haskins said:
GOOD NEWs the NW2 is back in service. I traced the wire to the circuit board for the rear truck, I knew it was a issue with the red wire since I was able to jump around like I stated in the post before. I put power to the red wired side of the truck and touched my multi meter probe to the wire and soldered contact and BAM the wheels were turning. I tried it again and the wheels were turned again. This contact and wire looks perfect but NOT, so I applied some heat and resoldered it. So far so good. The engine is back together and we are heading out to hit the rails and move some freight around. Thanks for all the help guys. Todd
WOW Thats just great, As you know and most others as well. USA Trains Rocks. Try that with DCS or Aristo. Thanks for posting your findings. As I already knew, USA Trains rocks…
(http://freightsheds.largescalecentral.com/users/nicholas_savatgy/_forumfiles/96_lg_clr.gif)
YOU BETCHA lol Nicky
I do like my USAT. I have a bunch of their rolling stock and 2 engines.
Greg in your photo the board closest to the cab closest to the body mount, the 2 terminals you can plainly see one is a red wire the other black. It was the red one that was causing the problems. Looked fine.
Thanks again.
So exactly what Paul Norton was talking about, although not frayed but a cold solder joint.
Nevertheless, sounds like Paul’s experience was the right place to start looking.
I’ll file this experience and Paul’s advice away for future reference.
Greg
Hi Greg! The area of the USA Trains PCB that I was referring to is outlined in yellow. This is where the motor and track power pick-up wires are soldered to the PCB.
(http://freightsheds.largescalecentral.com/users/son_of_a_cnr/GP9PCB.JPG)
I have found that the insulation on the wires does not meet the board and the exposed strands are oxidized and brittle. Many times I have found the wires hanging on by just a strand or two. If the wires or connectors are handled when installing a battery power, sound, a receiver or decoder; the wires at the PCB often break. Over the years I have often had to remove the solder from the traces and drill out the broken wires. The oxidized wire ends are then cut, and clean wire exposed by removing a bit of insulation. After soldering in the clean wires, ensuring the insulation touches the PCB, the board is cleaned with flux remover. Hot glue is added to the base of the wires as shown to provide stress relief and eliminate oxidization. I think header and connectors, like those used for the lights across the board, would be a better than having clunky 2-wire connector sets and soldering the wires to the board without stress relief. I don’t understand why the 2-wires connector sets are used at all, as the wires already have slip-on connectors at the motor blocks. Having this many connections just increases the risk of poor conductivity and radio frequency interference. I like my USA Trains diesels, but like any large scale product they do require some TLC; especially if they are modified for battery power, sound, decoders or receivers.
Paul Norton said:That is what I thought you meant Paul and exactly what I encountered myself
I have found that the insulation on the wires does not meet the board and the exposed strands are oxidized and brittle. Many times I have found the wires hanging on by just a strand or two.
Nicholas Savatgy said:
WOW Thats just great, As you know and most others as well. USA Trains Rocks. Try that with DCS or Aristo. Thanks for posting your findings. As I already knew, USA Trains rocks…(http://freightsheds.largescalecentral.com/users/nicholas_savatgy/_forumfiles/96_lg_clr.gif)
YOU BETCHA lol Nicky
How does a broken train “rock”?
I really like the conectorts they use…but they all get removed and re-purposed for radio/battery. All the plug wires are unsoldered, motor leads connected to throttle output, reversing relay output connected directly to lighting board. But, even for track power, the first thing I do on Arrrrgggghhhhhristo, USA, or Botch boards, any and all wires not to be removed get hot-glued in place. Seals out weather, and subsequent corrosion, stops wires breaking from vibration. In the past, Botch stuff has been the worst, especially the little wires for the flicker lights…I lift the wires vertical, lay hot glue down on the edge of the board, immediately press the wires down, when set, lay a bead across the top. Big 2-6-0’s, OF 2-8-0’s, but the newer Botch units get fully gutted so I get to start from scratch anyway.