I have something to say NEVER get a digitrax decoder. Me and one of my friends bought some and when we tried to run his train with the decoder, it burned up and I burnt one of mine up when I reprogrammed it.
i have had a similar problem with some of the dh123 decoders. a couple burnt out, and a couple more have had thermal shutdown issues. when they heat up, they shut down stranding your train until the cool.
might i suggest talking to digitrax tech support to see if they can help?
Burned up a decoder just programming it??? Did you boys perhaps take the shell off the locomotive to do the reprogramming? Or were you programming to something other than the factory defaults right after installing the decoder but before you test ran it? Did you install some very old Digitrax decoders? Their present production decoders are internally protected against overload (they shut down) and against motor shorts (they flash the headlights) but after reading the manual, I am sure you knew that. What you may not have know is that they are NOT protected against input-output shorts so if you do not properly isolate the motors, they can go up in smoke. What tests did you perform to make sure the motors were properly isolated?
I would really like to hear just what you did and did not do with your installs. I would also like to hear how you made out installing other brands of decoders. Then one of us may be able to give you some helpful hints to prevent it happening again next time.
Jim
Jim-
I actually ran the locomotive with the decoder in it but when I programed it to a different number, it fried litterally. I am using the DH123.
That is freaky. I hope you will contact Digitrax about this and post their response. Enquiring minds want to know.
Jim
what wtierce has said about the dh123 is the reason i don't buy them anymore. i've never had anything similar occur with any other digitrax decoder, and the dh163/165s are reasonable in cost, certainly much less than the cost of replacing a dh123 in kind.....
I'm really curious about this, as I've been using DH123's in my old Athearn locos for years and never had a problem. If you find out what happened please let us know.
Len
Quote from: Len on March 20, 2011, 09:13:16 PM
I'm really curious about this, as I've been using DH123's in my old Athearn locos for years and never had a problem. If you find out what happened please let us know.
Len
I really don't expect this person to answer. I think he just wanted to let off a rant.
Thanks for the suggestions, I was thinking about taking back the decoder after I get it fixed and just get a three pack of Bachmann Hard wire decoders of maybe a different digitrax decoder.
Iwas the friend we were putting the first one that burnt up like instantly it was in a 1952 Lionel southern pacific 4-6-2 YES it is ho scale runs great with out it though
Quote from: sly on March 24, 2011, 03:39:59 PM
Iwas the friend we were putting the first one that burnt up like instantly it was in a 1952 Lionel southern pacific 4-6-2 YES it is ho scale runs great with out it though
You problem is fairly obvious, your decoder was not rated for the amount of amps your locomotives draw. With old locos from the before 1965-1970 or thereabouts, the locos will draw considerably more. I have an old American Flyer HO loco that draws a little over 3 amps, I would expect Lionel locos from then would be in the 2.5-3 amp range also.
I hooked mine up exactly like it said and actually ran it until I tried to program it to another number. The loco that I had is a Life-Like Teakettle and is fairly new. What decoder would you suggest for the Lionel and mine?
Keep in mind that the DZ125 is basically a Z-scale decoder. But you can use it in N and H0-scale locomotives that draw less than 1.0 amp running and less than 1.25 amp stalled at 12.0 volts (I think Rich was thinking of the DH123 when he mentioned 1.5 and 2.0 amps.)
Next time, do the stall current test (how many amps the motors draws at 12 volts dc with the shaft held from turning.) The decoder MUST be able to handle this much current when the motor starts up. It only takes a few minutes when you have the locomotive opened up anyway, and all you need is a low cost digital multimeter (about $5) and a dc power pack capable of handling the load. For the record, many new locomotives draw less current, something around .5 amps. But I test them all anyway and occasional find one that draws more than it should even though it is new from a sealed box.
Many years ago, I had a Tenshodo brass FT. It pulled close to 3 amps running light. Figured it had to have a short in the motor so I rewound it. It still drew almost 3 amps. Checked the diameter and length of the wire I had pulled off, then calculated the expected current at 12 volts. It was well over 3 amps. The motor drew so much that it was dragging down the voltage of my power pack. I used it as a paper weight for a quarter century or so until I finally replaced the chassis with a chassis, motor and all, from an Athearn F-7/9. With the brass body and the Athearn lead weight, it will pull stumps. My point is that these old locomotives can draw a surprising amount of current. If you want to run them with today's electronics, you may have to replace the motor or even install a whole new chassis to get them to play nice together.
Jim
Quote from: wtierce on March 24, 2011, 07:28:44 PM
I hooked mine up exactly like it said and actually ran it until I tried to program it to another number. The loco that I had is a Life-Like Teakettle and is fairly new. What decoder would you suggest for the Lionel and mine?
Measure the current at 12 volts DC. Below is a link to a multimeter I use. I have three of these meters. Get the cheapest one.
They work very well with a DIY DCC amp meter.
http://www.harborfreight.com/catalogsearch/result?category=&q=multimeter
Rich
I will have to tell Sly that about the motor unless he sees this post again. He really didn't want to change the motor out in it but I still don't understand the thing about my engine. It is relatively new.
wtierce
Thank you for coming back with updates as I was interested in your Digitrax decoder problem. I use them in 9 of my 11 engines.
So many original posters never do reply the the responses.
wtierce-
Remind your friend that he can hang on to the original motor and any other gear so it can always be restored to OEM condition. This would be important if the loco turns out to have some collector value. I have no idea of the chances of that, but he might feel better about an upgrade/update if he knows he can always go back to nature.
-- D
Quote from: wtierce on March 24, 2011, 08:11:10 PM
... I still don't understand the thing about my engine. It is relatively new.
There are all kinds of possibilities. Perhaps a previous owner used steel wool to clean the rails. Motor magnets love this stuff and will suck it into a motor faster than you can blink an eye. Sometimes a bit of iron, for example a coupler screw, will end up in the locomotive and short from frame to motor or a bit of bare wire or solder will do the same thing. These or anything else that cause an inadvertent connection between a rail connection and a motor connection will blow a decoder. At least you haven't had the problem one young fellow had - he blew five decoders before he finally gave us a detailed, step-by-step list of exactly what he did to install them. He was putting them into an Athearn's locomotive, one of the ones with a flat springy metal strap that connects the top motor brush to the front and rear truck and to the headlight. Turned out he was putting that strap back in place each time he installed a decoder, not realizing it connected the orange decoder output wire that went to the top motor brush to the red decoder input wire that connected to the right hand wheels. He thought he had the motor isolated because be had put tape under it. But he forgot that an input to output decoder connection is an non-isolated motor, no matter how or where the connection is made. And an input to output connection on a decoder will blow the decoder every time. There are many ways of getting an unwanted connection. For example, getting a decoder wire caught between a locomotive shell and part of the frame. It may work for years until one day the insulation gets squashed or worn off and the wire conductor touches the frame. If it is the right wire, good bye decoder. When is this accidental contact most likely to happen? When you pick up the locomotive, such as to put it on a programming track. I don't say this IS what happened to your locomotive. Just an example of what CAN happen.
I hope this experience will not turn you off DCC. I hope you can look at it as a learning experience, just like your friend's locomotive. From that you learned the importance of measuring motor current BEFORE you select a decoder. Whether we like to admit it or not, that is a lesson most of us have learned, and mostly we learned it the same way. It is just a little easier to accept if it is the tenth decoder you install that burns up rather than the first.
Jim
I didn't get the train from another person, I got it brand new for Christmas a few years ago. Also, Sly knows that he can keep the motor.
NCE makes some decent decoders and they are reasonably priced and they provide alot of info about them that digitrax dosen't. i haven't had any problems with them yet
i have a question about the nce decoders. i believe the ones i have are d13sr. do these support switching speed the way digitrax does? on the digitrax decoders you can use function 6 to cut the locomotive speed in half for yard work (or to slow down your kid's locomotive)........
Like Digitrax decoders you can program the max speed via cv6 on your program track to limit the max voltage that goes to the motor to keep the locomotive from running at top speed. If cv6 is programmed as 0 the the max speed is defaulted at 255 which is full motor voltage for max speed. any value less then 255 lowers the max speed of the locomotive. 128 would program it to be about half speed for the maximum and anything lower would be less max speed. 65 would be about 1/4 for the max and 192 would be equal to about 3/4 for the max.
sorry that was cv5 for the max speed - you should set cv6 for half of what cv5 is because that is your mid speed which means you get smaller increases in motor speed through the lower ranges rather than taking off like a rocket to the setting of cv5 as you increase the throttle setting- more protoypical rather than "stomping on the gas" so to speed as you accelerate from a dead stop.
Sorry I failed to answer your question. I am not sure that they use the F6 or not to set switching speed. I just have programmed certain locomotives for full time switching duty speeds and use them exclusively in that role. I will have to find out if that can be done. But for a child's locomotive to keep the speed from being at max all the time i would just reprogram it for a lower top speed.
I installed a DN135D decoder in a new HO Bachmann Spectrum GE 44 Ton Switch Engine. Decoder wires are soldered to terminals on the engine's pc board (H800X-PCB01) per parts drawing. At slow speeds (8-12 on Digitrax DT402 throttle) it operates fine. However at speeds above 15 (a moderate switcher speed) the decoder looses control, i.e. it won't slow down, stop or reverse unless I lift loco off the track. Then I can restart it. The decoder is only connected to the motor, not the headlamps.
I am suspicious that several components on the Backmann loco's pc board may be the cause. There are two 1µF ceramic disk capacitors and two small wirewound chokes. There were no instructions accompanying the locomotive recommending disconnecting either the caps or chokes if wiring for DCC. Has anyone had a similar experience with this or other Bachmann locomotives & Digitrax decoders?
Quote from: flrailroads on March 28, 2011, 11:04:38 PM
Has anyone had a similar experience with this or other Bachmann locomotives & Digitrax decoders?
Control problems with silent decoders are often caused by those capacitors you saw. Cut them out or clip just one lead and swing them out of the way if you want to keep them handy.
Jim
Jeffery,
I did some more research and as far as I can tell about NCE decoders is that they don't have the reduced speed switching mode that digitrax does. I don't have access to check it out as my locomotives are on a railroad museum layout so I will have to check it out next time I am there and see if they do. However from what I can tell from my literature I have on hand I think its safe to say no they don't. As i said you can just reprogram the appropriate cv's (5 & 6) for the desired speed for switching for true full time switchers if you have units you can and are willing just to dedicate to that end- full time switchers that is, otherwise for road locomotives or road switchers that would be a pain having to reprogram just for switching service and then have to reprogram again to go back to just mainline service only. But I am curious about it now and perhaps that is a suggestion that should be made to NCE about future decoder models or revisions to their existing line of decoders.
that's what i was afraid of. i think it's cv57 that you have to set. the nice thing about this is that you can have your switchers set to run at this speed permanently, and the road power set to use switching speed in the yard, or when there is a switcher in the consist. real life switchers were often restricted to 40 mph due to their trucks anyway, and this would be an interesting wrinkle in operating the layout.
57 or 54, one of those 2. It says in the DS13sr decoder literature that some cv's including those in the 50's can be programmed but will be ignored so that would preclude the instant selection of switching speed mode. So you would have to stick with Digitrax decoders for that luxury of instant change to the switching speed mode.
Yes, most switchers were capable of faster speeds depending on the gear ratio applied - the lowest gearing on EMD units allowed 55 MPH but due to those hard riding AAR type A switcher trucks underneath the units most switchers were limited to 35 mph. You could go faster but you probably would have been shaken to death in doing so. If the switcher is a working trailing unit in consist with no crew on board a higher speed would be ok because the crew wouldn't get rattled around. You would just have to watch the max speed so the unit wasn't overloaded and burned up something in the somewhat primitive electrical systems, or the components thereof, of the time when they actually built units just as pure switchers for yard or light road service switching capability. If just towed along in consist idling and isolated or dead in tow then it wouldn't be an issue as to how fast it went other than it may shake something loose on the unit from vibration.
Interestingly and oddly enough- NC&StL and Alaska RR had GP7's , and perhaps other roads and/or other models, that were factory equipped riding on AAR type A switching trucks. I think that eventually they were probably changed out for the normal Blomberg road truck after enough crew complained about the rough ride or they found out it was hard to use them at other than lower road speeds- it would be akin to driving your vehicle with the shocks taken out.
ref: Reply #24
Thanks to Jim Banner's reply (#25) I disconnected the two 1µfd ceramics on loco's pc board and the decoder now remains in control of loco :)
I just got my RS-3 back from the DCC installer with a Digitrax DZ143 in it and the loco runs perfectly even after I re-prorgammed it. The installer tested the decoder at his shop before I picked it up.
Sorry for no updates. I am using the DH123 so Jim, you put the DH125 while I am almost positve that I put the type somewhere but sorry if I didn't. I put the one good decoader in my Thomas and it works fine. I don't know why the first one burnt up. I cut the plastic off of it and a tiny rectangular piece was burnt up. That is all that was wrong but I don't know how to fix it.
Many of the tiny pieces are resistors. When one burns up, it is usually a result of a failure within one of the integrated circuits (slightly larger pieces with many connections.) Replacing a surface mount IC is virtually impossible without special equipment. Even finding a replacement is difficult to impossible. It is the price we pay for miniaturization. Fortunately, for what we get, the price of a new decoder is not very high.
Jim
Thanks
I had one or two Digitrax DCC decoders fry on me, but I thought that that was just me and my mistake. After what I am reading now, maybe not.
I am curious. If not a Digitrax DCC decoder for an old Athearn engine, what would any of you recommend? Would this other DCC decoder fit the Athearn harness made by Digratrax? Would it be the NMRA 9 pin plug that you could just plug into the Digitrax harness?
I had an unusual case of "letting the smoke out of adecoder. Yes--it was a Digitrax, and yes, they replaced it.
I had installed the decoder in an old (1964) Max Gray HO SP 4-8-2. I had replaced the motor with a Sagami 2032 whose current rating was well within that of the decoder. Due to limited space in the boiler I had used an N-scale decoder. I was running it on our club layout for quite a while when suddenly the smoke leaked out. In order to make a neat job, I had given the decoder a couple of twists to keep all the wires together Apparently the wires were too light for the job, as they heated up until the power wires melted thru their insulation and shorted out.
gj
Mine smoked to. So you think they'll replace it?
Maybe the Digitrax website is the best place to discuss their products......
Ordinarily, yes--but the circumstances in this case could probably happen to any brand--the combination of light gauge wires, twisted, overheating and melting the insulation crerating a short circuit gj
My experience with a variety of different brands of decoders is that decoders fry for three reasons:
(1) improper installation, either a motor that was not isolated properly or the installer failed to properly measure the current requirements of the locomotive. A stall test on each and every locomotive is a must, and keep in mind that the required current rating is the total of motor current AND function currents.
(2) failure of a locomotive component outside the decoder. This can include a motor that fails and suddenly draws excessive current or a motor that was faulty right from the factory. Occasionally, when a light bulb fails, it shorts instead of going to an open circuit. This will almost always cause an immediate decoder failure. And wiring, particularly wiring insulated with tape instead of shrink tubing, may short and many of those shorts can fry a decoder.
(3) a component or assembly failure inside the decoder itself. I routinely test new decoders on a decoder tester I built years ago out of a small gear motor and a bunch of grain-of-wheat bulbs. Very rarely have I found a decoder that was defective as received. Interestingly, I have never had a company question a returned decoder when I tell them it was tested on my tester before installation.
I don't mean to discourage anyone from installing their own decoders. Even if you fry the occasional one, it is still cheaper than having them installed. And if you follow good working practices, including appropriate testing, your failure rate should drop to near zero.
Jim
Sorry Yardmaster. The thing is is that this is the only forum account I have and honestly don't want to create another just for that.