I've got a recently-released Atlas GP38 that is giving me dcc problems.
I've read other threads (usually regarding Bachmann) about capacitors on the light board that interfere with proper dcc operation. I'm wondering if that's the case here.
Some background: I received the loco about 10 days ago. This was the "DC, dcc ready" version and I had read that it came with an 8-pin connector. OK, I have a few spare 8-pin decoders (Digitrax, TCS).
It ran ok out-of-the-box on a short test track using DC.
I took the shell off, and found there was not only an 8 pin connector on the board, but a 21 pin as well, with what looked to be a "dummy plug" plugged into it.
I pulled off the 21 pin dummy connector, and tried a TCS 8 pin decoder. The engine ran and I should have left it that way, but the headlights were giving me problems. Time to try another decoder.
Swapped it out for a digitrax DH166 or 126. Now... doesn't run.
I'm using a Roco z21 running on a Samsung tablet, so went to the programming pane and tried some basic commands. I was getting an error message to wit: "command could not be entered, decoder failed to respond". I don't recall ever seeing that error before (and I have at least 25 other locos).
Hmmmm... maybe the 21 pin dummy plug is supposed to remain in place? I put it back and... POOF! Smoke from the 8 pin decoder. Nope, that's not it.
So I took off the 21 pin dummy again, and re-connected the TCS decoder -- and now, it won't work, either.
In fact, none of the other four 8-pin decoders I have would run the engine. The lights would activate, but the loco wouldn't run.
So... I ordered an ESU LokPilot 5 21-pin decoder. I have older ESU decoders in three other locos and they work very well.
Put the LokPilot 5 on the 21-pin connector and the engine runs and lights work. BUT... it doesn't seem to run as well as it should. Speeds up and slows down on its own, as if the decoder wasn't sending the right signals or voltage or something.
So... As mentioned above, I'm wondering if this engine has the capacitors somehow interfering with proper operation of the decoder.
Nearly all my other Atlas engines are "older stock", probably before the manufacturers started putting in the capacitors per European requirements (I believe that's the reason?), and none of them ever gave me problems like this.
I think the capacitors are the two "red canisters" on either side of the lightboard in this pic? (the pic is not my GP38, but the red canisters are the same)
Should I snip the connections to these? Is that the right direction to go?
Thanks for reading.
OE,
Since you outfitted your GP38 with a LokPilot, try running the Auto-tune feature before snipping off any caps. To do this:
Either do this on a roller test stand or on a 6' length of track because the locomotive will take off at full throttle for 2-3' then suddenly stop. It might fix your issue...or it may not. It's worth a try.
You could also try hardwiring the decoder rather than use the 8-pin socket. You'll need to add resistors if your headlights are LEDs or 1.5V incandescents.
Tom
https://tstage9.wixsite.com/nyc-modeling
Time...It marches on...without ever turning around to see if anyone is even keeping in step.
tstage:
I tried the "auto-tune" previously, didn't fix the problems.
I've considered tearing out the existing wiring for a "new board", but...
... that seems overkill for a new/recent engine.
I may try a different 21-pin decoder, perhaps a Soundtrax. I've used ST products and have been satisfied with their performance.
If a Soundtrax decoder behaves the same as the ESU, may have to tear out the factory wiring. But again, this shouldn't be necessary on a new product.
I considered it could be "mechanically-based", but the motor/drivetrain turns freely by hand, with no indications of binding, etc. ...
I would think after the 3rd decoder attempt that the board is the issue and trying yet another decoder would be a waste of $$$.
I would try removing the current lightboard completely and "temporarily" hardwiring one of the decoders to the chassis wiring to see how it runs. If that fixes the issue then you can either 1) hardwire your decoder of choice permanently, or 2) use a Decorder Buddy board for making your connections. I've never tried the latter personally but users seem to be pretty happy with them.
You might also want to confirm with a multimeter that the motor brushes are isolated from the chassis. Some older locomotives are not isolated and this could be problematic should you inadvertently derail and the magic smoke is released from your decoder.
I think that you need to remove the 8 pin plug. Bet it has pins shorted so it would run on DC.
I know the capacitor issue came up with some early "DCC ready" Bachmann engines, I don't know that it ever was a problem for other manufacturers.
I suspect the second decoder had a problem before being plugged in, could be the first one did too (or if it needed some adjustments re the lighting)? Also, I wonder if the 'puff of smoke' you saw that apparently fried the one 8-pin decoder didn't also affect something in the greenboard and that is causing the trouble with getting an 8-pin to work.
If the engine is now working with the 21-pin decoder but just not running as smoothly as an Atlas engine should, you could (if you haven't already) do a break-in run: 10 min. or so forward at about 3/4 full speed, then 10 min. in reverse. Then maybe lubricate the moving parts. That could be all it needs at this point.
I miss read your post- I was thinking you were using the 21 pin connector to use a decoder- not sure why you destroyed a decoder using the 8 pin plug as long has the 21 pin jumper was removed.
better take a good look at the light board for a short some place.
The engine runs (movement, lights) with a 21-pin decoder (ESU LokPilot 5).
There is nothing in the 8-pin connector with the 21-pin decoder attached.
BUT... although it runs, it seems to run erratically. It will suddenly "jump up" in speed -- as if I put on 15 more speed-steps (but nothing has changed). It seems more "electrically related" than "mechanically related" to me. As if the dcc board was reacting to inputs that I didn't make.
And then... it will go back to running ok. As if a switch had been flipped on/off.
The drive train doesn't seem to be binding up. Something else. I could be wrong.
This is a relatively new release -- Atlas HO product archive shows these as having gone into production around 2018. Conrail #7880 with the "white stripe".
Since I can't get any 8-pin decoder to work, I'm going to try a second 21-pin decoder (which I don't have yet), and see if the problems recur with that...
I still think you should try removing the lightboard before purchasing another decoder. Then you'll know for sure whether the lightboard is the source of the issues or not. But that's just me...
I sympathize with your problems. I've had one decoder fry on me in 16 upgrades.I must have really old stock because I've not seen a 21 pin socket on a GP38 either. The 2 GP38's I have are really old and had filament lights no less.The GP38 is probably the easiest loco I have ever had to plug in a DCC board. Remove the dynamic brake cover on top and slide it in and shove the sugarcube speaker in there as well. Yeah, old stock release....My GP38-2 had LEDs and was a 5 minute DCC upgrade with a Loksound v5 DCC (58820). I wish they were all as easy. (Looking at you Atlas Dash8....)However, back to being relevant, with my GP38, what I did was get a Loksound 5 DCC Direct (58821) and simply replace the entire light board assembly and wire in some LEDs. Easy job and no Atlas electronics remain in there. A bit of soldering was all it needed.
Good luck sorting this out.Like others have pointed out, I'd not be using that existing lightboard any more.
woodone...not sure why you destroyed a decoder using the 8 pin plug as long has the 21 pin jumper was removed.
He put the 21 pin jumper plug back in (with the 8 pin decoder still plugged) in when he couldn't get the 8 pin decoder to program.
OldEngineman...although it runs, it seems to run erratically. It will suddenly "jump up" in speed -- as if I put on 15 more speed-steps (but nothing has changed). It seems more "electrically related" than "mechanically related" to me. As if the dcc board was reacting to inputs that I didn't make. And then... it will go back to running ok. As if a switch had been flipped on/off.
Is it possible the loco is selected on more than one throttle? That's exactly what it sounds like but I'm not familiar enough with Roco to know if it's possible.
CSX RobertIs it possible the loco is selected on more than one throttle? That's exactly what it sounds like but I'm not familiar enough with Roco to know if it's possible.
Maybe check that the decoder wasn't at some point added to a consist? That can cause similar problems.
The OP stated he had purchased a LokPilot 5 decoder to try in the locomotive so that shouldn't have been in any consist. The idea by Robert that the locomotive might be acquired by more than one throttle has some merit.
Oldngrey wrote: "However, back to being relevant, with my GP38, what I did was get a Loksound 5 DCC Direct (58821) and simply replace the entire light board assembly and wire in some LEDs. Easy job and no Atlas electronics remain in there. A bit of soldering was all it needed"
That one looks like it would drop right in, BUT, I don't want sound. Just motor control. $90+ is a lot for a decoder that's only going to be used for motor control..
To answer wjstix -- I have no "consists", the railroad and the way I run it is too small for that. Every engine I own runs "as a single unit".
A gripe: I had good experiences with ESU decoders up until this one. I have three other ESU units, all three have the #53614 21-pin decoders, and all three run great.
But the 53614 has been superseded by the #59629, which is what is in the GP38. And, compared to the older decoder, this new one has "feature-itis". A bit too complicated for my tastes, particularly the function table setup (as accessed using JMRI).
I'm thinking of trying a Soundtrax 852005 just to see if it improves things. I believe the ST is "more basic" and I'm really just interested "in the basics", anyway.
Oldngrey I sympathize with your problems. I've had one decoder fry on me in 16 upgrades.I must have really old stock because I've not seen a 21 pin socket on a GP38 either. The 2 GP38's I have are really old and had filament lights no less.The GP38 is probably the easiest loco I have ever had to plug in a DCC board. Remove the dynamic brake cover on top and slide it in and shove the sugarcube speaker in there as well. Yeah, old stock release....My GP38-2 had LEDs and was a 5 minute DCC upgrade with a Loksound v5 DCC (58820). I wish they were all as easy. (Looking at you Atlas Dash8....)However, back to being relevant, with my GP38, what I did was get a Loksound 5 DCC Direct (58821) and simply replace the entire light board assembly and wire in some LEDs. Easy job and no Atlas electronics remain in there. A bit of soldering was all it needed. Good luck sorting this out.Like others have pointed out, I'd not be using that existing lightboard any more.
Not to hijack a thread but could you tell me what decoder you used with the sugar cube speaker and 8 pin plug.
I have the same Atlas Locomotive but with a notor only decoder.
Joe Staten Island West
OldEngineman...To answer wjstix -- I have no "consists", the railroad and the way I run it is too small for that. Every engine I own runs "as a single unit"...
No thoughts on whether or not it could be selected on more than one throttle?
Robert wrote: "No thoughts on whether or not it could be selected on more than one throttle?"
Sorry, this makes no sense to me.
I use a Roco z21 control box and for my control surface I use a Samsung 9" tablet. Every loco (about 27 or so now) is represented by its own screen, I use a horizontal orientation so I have 2 locos side-by-side at any time. When I select a loco, it's number and pic is displayed, and no two engines have the same number.
GP38 7880 (the one that has the problem) can't be controlled from any other loco's screen. Whatever is affecting it is something "self-contained" to/in that unit.
Since my 8-pin decoders won't work with it, I need to try another 21-pin decoder, but don't currently have one at the moment. So this is on the back burner until I find another to try...
OldEnginemanRobert wrote: "No thoughts on whether or not it could be selected on more than one throttle?" Sorry, this makes no sense to me. I use a Roco z21 control box and for my control surface I use a Samsung 9" tablet. Every loco (about 27 or so now) is represented by its own screen, I use a horizontal orientation so I have 2 locos side-by-side at any time. When I select a loco, it's number and pic is displayed, and no two engines have the same number.
With some DCC systems, it's possible to have a loco address selected on more than one throttle at a time (the "throttles" don't necessarily have to be physical throttles, for example, on the tablet each screen is probably a seperate virtual throttle). When that is the situation sometimes what happens is the loco will run fine but will occasionally jump in speed (or slow down or stop) for a time and then return to its previous speed as the command station switches control between the two throttles.
Again, I'm not very familiar with your Roco systems so I don't know if it's possible with it (can you have more than one screen set to the same address?), but when you described what the loco was doing that's exacly what it sounded like.
A followup.
I got ahold of a 21 pin Soundtraxx decoder and tried that in place of the ESU decoder.
The engine still runs "on the choppy side" at mid-low speeds (speeds up, slows down, speeds up, slows down, etc.)
I find this to be VERY untypical of an Atlas drivetrain. But then, this may be the only Atlas loco I have that is recent enough to have the capacitors on the light board. (I've got an Atlas AEM-7 -- but don't remember if that has capacitors in it, or not)
I also noticed that the motor seems to get on the warm side, considering there's not much of a load on it (just running light).
Turning the flywheel by hand, nothing seems to be binding.
Maybe this one is just a "dud out of the box"...
I suspect that the Atlas locomotive is fine; it's the lightboard that's the issue. As I suggested in a previous post, I would completely remove it from the equation and hardwire the motor and track power leads to any one of your three decoders to see how it runs. I'm going to guess you'll see much improvement in the operation of your GP38.
The capacitor "issue" was something that came up with Bachmann engines maybe a decade ago, it has nothing to do with Atlas.
If multiple decoders have been tried and there's still a problem, it's not the decoders. Given you had a puff of smoke early on, most likely something in the lightboard is fried. Removing capacitors won't help. Just remove it as has been suggested and maybe add a "Decoder Buddy" so you can use your 21-pin decoder, or just hardwire in a 9-pin harness so you can try one of your other decoders in it.
Tstage, I don't do "hard wiring".
I DO do re-wiring with the appropriate board or adapter.
Well, I tried clipping off what looked to be capacitors (see pic in first post). Now the lights still work but the engine won't move. So I blew that one. I've taken the factory light board OUT of the chassis.
I can't put a "pre-fab" dcc board (such as the Digitrax DH165LO, which is specifically made "for Atlas") because the "cutout" into which the factory board fits into the locomotive weight is 53mm long, and the decoder is longer. I'd have to machine down the weight, and I have no ability to do that.
What I COULD do is wire all the leads into one of the old "8 wire adapters" that Proto 2000 used to use in their engines. I've used these before and like them VERY much. The problem is that they're no longer made and difficult to find.
These have an 8-pin (female) plug ready to plug in the decoder of your choice. They also have 4 "tabs" on either side, so you can attach the leads either by soldering or by using those little plastic "retainers". I prefer the retainers and use them on most of my engines, and have had minimal problems with them.
Here's what the 8 wire adapter looks like (marked "P8"):
I'm wondering if any forum members might have a few of these they no longer need nor want...?
OldEnginemanTstage, I don't do "hard wiring". I DO do re-wiring with the appropriate board or adapter.
Does that mean you don't like to solder or you prefer to minimize it as much as possible?
All I suggested was to temporarily wire the decoder to the locomotive to confirm that both work properly together in the absence of the lightboard. Then you know the lightboard was the problem. Once that's confirmed you can wire it however you want to.
OldEnginemanI'm wondering if any forum members might have a few of these they no longer need nor want...?
Hi, O.E.
I just dug through my bucket of PC boards and found a bunch of the diode-filled light boards and two FOUR of the "P8" plug-ins.
I had recently sent off a bunch of dummy plugs and the little plastic clips and other wiring hardware to another forum poster so my "stock" was running thin.
My email is in my profile OR you can PM me if that works, with your address.
Good Luck, Ed
LastspikemikeIt will not likely look pretty but it won't be hard to do.
You can make it pretty with a good mill file
IMG_2849fix by Edmund, on Flickr
(I removed all electronics before making any modifications to the weight. You don't want filings in the commutator or PC board)
Regards, Ed
Beautiful job, Ed!
gmpullman wrote: "My email is in my profile OR you can PM me if that works, with your address."
Thanks for the help, I've sent an email to you. (actually 2 emails)
LastspikemikeYou can cut a locomotive weight with an ordinary hacksaw. These are very soft metal. Milling is serious overkill.
You couldn't for milling a channel in a chassis like this...
I had to do that for a DCC conversion of an old Walthers SW1 switcher years ago. Thankfully I had access to a Bridgeport at work and purchased my own 2-fluted endmill to complete the task.
OldEnginemanThanks for the help, I've sent an email to you. (actually 2 emails)
Got 'em. Glad to help!
tstageI had to do that for a DCC conversion of an old Walthers SW1 switcher years ago.
Thanks, Tom! I like your work, too. I "lost" my machining capability back in 2016.