Decoder Failures 7 out of 10

[Rayd60]

A little help please.
I have a 15 x 10 HO layout twice around with two hidden reverse loops. Digitrax DCS240 and a DT500D throttle. Out of 10 Loco’s I have had to or will need to send back 7 for decoder issues. 4-BWL SD9’s & a few BWL steam and now a new Athearn SD40T.
The only locos that have not failed is a Scale Trains SD40-2 and a BWL 2-10-2 they run perfect and have been running for weeks.

These locos fail say in the first 10-mins out of the box most of these would still run fine in DC including sound just stop ruining in DCC and some like the SD9’s repeated this failure after a decoder reset. They run fine without a load then with 10 freight cars tie to any one loco they stop running after 10-mins. I did a reset on the DCS240 but then the Athearn failed no load. Most the address are readable but like the Athearn nothing. I write this because of the Athearn failure. BWL will allow a return on the SD9's I have not contacted Athearns yet, this just happen. I have not placed any of the previous repaired BWL locos on the rails.
I need to know what is going on before I place any new or repaired engines on the rails.
Is there any possibility that the DC240 is at fault? I can't think of a reason but I am reaching. 7 out of 10!
Thank you.
Ray D

[rrinker]

 What exactly is the failure? Do they move and then stop, move and then stop? That is often a sign that you have the same address selected more than once, and one is set to speed 0 and the otheris the one you are trying to control witht he throttle knob - so the loco will move, then stop, or suddenly change to a differen speed, then come back to the speed you have on the throttle in hand, over and over.

 Remember to clear each loco when you are done runnign it - set the speed to 0, turn off all functions, and then press Loco, and Exit. Now select the next loco you want to run. Repeat each time you switch to another loco.

 A reset of the DCS240 will clear this information, but you have to do the correct reset - which one did you do? Remember to check the OpSw section int he back of the manual - there are many web sites that come up if you google "digitrax command station reset" but man will be for the older DCS100 and some things have changed. The DCS240 instruction book will have the correct options to use.

                                     --Randy

 

[selector]

The wide variety of locomotives, and their large number, suggest to me it's a problem with the system or the operator, perhaps both.  That many decoder failures is extremely unlikely.  I have never, in my 13 years on this forum and many others, seen another such claim of trouble.  So, I'm inclined to agree with Randy that something isn't right with the DB, possibly with the tether to the DT, something not seated in a slot inside the DT, or the tracks are not passing on reliable power to those locomotives for some reason.

[Rayd60]

Two of the 7 came back from BWL fixed. The 4-SD9's went out today to BWL for service. I followed both Digtrax and BWL reset instructions and no changes kepting them both in the loop. I set up a loop of track on a table and connected to it directly with a UT4 and no change. The Athearn SD40T is complety gone no responce in DC or DCC. I have not contacted them yet. Take note I have been runing Scaletrains SD40's for weeks no problem along with a BWL 2-10-2, solid runners. 

If BWL comes back with no problems on the 4) SD9's I will find a new hobby! The 4) SD9's are the real odd ball in my mind.

Thanks for the reply.

Ray D 

[MisterBeasley]

Were these decoders factory installed, local shop installed, or home installed?

Have you measured the track voltage?

Did you get these new, or pick them up second hand?

[Steven Otte]

I had someone write in to Ask MR recently with a similarly perplexing problem. It turned out he was running his DCC system off a 15V power supply instead of a 12V one. Could that be your case?

[Rayd60]

The DCS240 requires a max of 24VDC I am feeding it with a regulated 22VDC @ 10A. It will operate properatly on lower voltage of 13VDC per Digitrax.

All of the locos are new out of the box bought from a BWL dealer, actualy two were purchase from BWL directly, from their remanufacture listing.

 

[Mark R.]

Steven Otte

I had someone write in to Ask MR recently with a similarly perplexing problem. It turned out he was running his DCC system off a 15V power supply instead of a 12V one. Could that be your case?

 

Definitely check track voltage. That is also one of the main reasons why the Athearn engine bulbs never lasted very long - too high a track voltage translated into the onboard rectifiers supplying slightly more than 1.5 volts to the bulbs ending their lives pre-maturely.

Mark.

[wvg_ca]

it seems likely that something simple is wrong, but you will need a multimeter and possible a rramp meter [or similar] to find out where it is ...  a good place to start is with the power supply used ...

i have been in the hobby for maybe a dozen years, and have yet to send a decoder back ..

[Rayd60]

Everything was walk through with Digitrax, first rate tec support by the way and BWL also great to work with. Everything was checked throughly and reset several times. As I repeat I have several locos that have been running just fine for months and continue to run just fine. 

Thanks.

[richg1998]

Yes, check track voltage. A RRampMeter is nice.

I use cheap Harbor Freight multimeters They show 13.6 volts AC on my NCE Power Cab but different meters might not show that. The DC supply is 13.9 vdc so close.

My Oscilloscope verifies. It shows peak to peak but I use math and it comes out close to what the meters show.

Rich

[BigDaddy]

If you are several volts out of wack, a Harbor Freight is good enough.