More DCC problems

[Mathew]

Sorry if this is long, I tried to explain it so that when you read it you see my problem.


Im in the middle of the road. First I started having problems out of an atlas unit which some of you said may be the board, easy enough. Now, I got two more units (MP15DC) that arrived yesterday used. The problem here is I dont know if its the units or my dcc system. On the one unit once I put it on the track, it works like it should ( for a few minutes or seconds) I can control the direction and lighting, then after running a bit, my contoler screen goes blank but the engine keeps going. Once I pick up the engine off the track, my screen comes back. The other unit, all I can get out of it is controling the lights. Ive tried taking my system ( MRC prod express) and hooking it to a piece of track on the kitchen table and still have the same problems. I did this to make sure my wiring skills on the layout was or wasnt the culprit. Im not sure where the problem lays if its in the two engines or my dcc system. I know once before when I ask about the atlas engine ( see loco problem(s) in this section) some said it was the board, some said it may be my system. Im beginning to think its my sytem.

[kcs1967]

Matthew
I am not a DCCer , but if loco runs and screen goes blank sounds like possibly something internal to the controller. Any friends nearby you could takey loco and test on their stuff, and maybe someone locally has MRC too, that way you could check your controller using their equipment.

[CIOR]

OK, lets start here first.
What type of decoders do each engine have in them?
Next, what happens if you put any other of the MP15's on the track?

I'm willing to bet there might be something wrong with the decoder in that one engine, if its the only one that does this.
You might have to do a reset and if that fails, then put in a new decoder!

[Mathew]

To try and answer all the questions.

I dont have anyone nearby that I can go test either item and I only have the one dcc system

As far as decoders, I checked back on my ebay page on these and it shows the decoder to be a Digitrax DZ125 Ill try a reset on the one and see what happens.

[Mathew]

I did the reset and it worked...... for a min. Now both are doing this..... As soon as either one touches the rail and gets power, they take off (slowly) and my screen goes blank, pick em up and the screen comes back.

[Mathew]

OK OK OK, well, I got it fixed i think. The problem I have now is that when my controler stops responding instead of going blank is shows SDVA. Ive reset both locos so now they both work but Im still having contoler problems.

[Mathew]

Mar 16, 2010 11:09:56 GMT -5 @laughinghippie said:

I've never heard of that happening unless there was a problem with the DCC system, sorry to say.

Thats what has me a little worried. At least now I got it figured to where I dont think its my locos, I think. But still its aggrivating that when I start getting things together, all the little bugs decide to show up.

[Mathew]

I think I may have found my short, however, I dont know if thats still the problem. One, is in one of the cheapy atlas switchs, and im not sure how to fix it. Its just odd cause ive not had problems until now.

[Mathew]

Well, upon further investigation I found I had multiple players against me. One being I had the wrong power cord plugged in to the power supply, it worked, just not like it should. Fixed that. I then did a reset on both locos and that got the one that wasnt working, working now. so thats fixed. Now instead of my screen going blank, when my contoler stops responding it shows the letters SDVA ( or something like that). So I got to watching the locos and I found one particular switch is giving fits. I can go across it one way, but on the way back is when the short occurs, how, I havent figured out yet. I think my "plan" on trying to keep my layout (since its my first one / attempt) on the cheap side has came back to haunt me. Its just strange that the one switch is where I seem to be getting the short, it doesnt occur on any of the others.

[kcs1967]

Matthew

When you say Cheapie Atlas Turnouts I am curious, How are the rails insulated, it could be you just need to insulate one or both of the turnouts rails. Granted again I am not a DCCer so I have no experience with this, but DCC is more sensitive to shorts than DC.

Per MRC site

www.modelrectifier.com/resources/trainSound/PRODIGY%20ADV%20TIPS%20AND%20TRICKS%20REV%2010-02-2009.pdf

"Prodigy Express and Reverse Loops-
The Prodigy Express because of it’s lower output rating, [1.6 amp.], is very sensitive to
short circuits on the layout. It will display the “SvdA” message on the display when a
short circuit or overload condition happens on the layout. When this occurs, unplug the
cable from the bottom of the handheld, wait approx. 1-2 seconds, then plug the cable
back in to regain control of your loco. The message should be gone. If not there is
most likely a problem somewhere on your layout. You will also get this message when
using a reverse loop controller such as our AD520 Reverse Loop Controller. The reverse
loop controller acts as a momentary short circuit as the loco passes over the insulated
gaps in the reverse loop. This situation can get annoying every time the loco goes through
the loop and you have to reset your handheld. There is an upgrade for the Prodigy
Express, which involves sending the complete system back to M.R.C. with a small fee.
This gets you a higher output power supply, [2.5 amp.], and a software upgrade to handle
the higher load output.


Search the document for SvdA, it shows evey instance SvdA appears, the above Re short circuit is most likely, Isolate the rails by cutting a gap and see if problem disappeas, or replace the turnout, $20 for a turnout is chaper than $50 for a decoder, I hope this helps.
Justin

[alcors1]

I can tell you the problem with that one switch, what is happening the wheel is being pushed across the frog and make contact with the other rail of the turn, this is the short, this is happening just before the wheel enters the frog. I have such problem with one of my code 83 atlas switches. The problem I have is not made by atlas but by me, after I filled in the track when making it into a concert scene (it is in a port), so I just removed some of the obstruction that was pushing the wheel against the natural flow it, it is solve. Another fix to paint the rail 1/4 inch on that corner so that part remains insulated.



this is the best way to explain.

I would also recommend upgrading to 2.5amps 1.6 is not much to play with especially if you ever get a MRC sound decoder, they are amp drains.

[kcs1967]

Mar 17, 2010 9:58:54 GMT -5 alcors1 said:

I can tell you the problem with that one switch, what is happening the wheel is being pushed across the frog and make contact with the other rail of the turn, this is the short, this is happening just before the wheel enters the frog. I have such problem with one of my code 83 atlas switches. The problem I have is not made by atlas but by me, after I filled in the track when making it into a concert scene (it is in a port), so I just removed some of the obstruction that was pushing the wheel against the natural flow it, it is solve. Another fix to paint the rail 1/4 inch on that corner so that part remains insulated.



this is the best way to explain.

I would also recommend upgrading to 2.5amps 1.6 is not much to play with especially if you ever get a MRC sound decoder, they are amp drains.

I agree with Warren

I would cut the around the frog and use a micro switch to power it. The paint would definately be the quick fix, clear nail polish would be cheap and quick.

[Mathew]

Well the atlas switchs I have, have the plastic frog. It seems that the first truck goes across ok but when the second truck starts across the switch, thats when the short occurs. Ive tried throwing the switch both ways to see if it does it in the one direction but it does it both ways.





Ill get in touch with MRC and see what the upgrade would cost. Ill also put the gaps as shown and if none of that works Ill try replacing the switch.

[alcors1]

I still think it is the wheel making the bridge.
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[kcs1967]

If The Frog is plastic, just the rail in the center, as that is likely the culprit, put some nail polish on therail before you cut to be sure it is the problem.

[CIOR]

Mathew, simple test.
Take some paint, paint the inside of the rails, both rails.
Then after dry, clean the rail head off, then test run the engine across it.

My suggestion is this!
Unhook the power to the layout, take a test piece of flex and see how the engine runs on just that.
If fine, then test the layout in segments. I've learned that even on a small layout that putting the electrical in segments you will be much better of when something occurs, as you can limit it down to that segment and further narrow your search limits!

[Mathew]

Update.... I did the nail polish trick. That narrowed it down to it being the switch so now I now what I need to do on that part and Ill also talk to MRC about upgrading my system. Ive been running now for approx 20 mins, so far no shorts. So, I think I figured out the culprit. In the process I also found a few parts of the track that need better connectivity so Ill be putting in a few jumper wires so that should do the trick. I think I have the problems sorted out now and I thank you guys for the help.

[kcs1967]

Hell Yeah that is great news!!!!!

[CIOR]

Try buying a circuit breaker from Tony's. I have 6 or 8 of them on my layout and they are worth every penny. They will protect your DCC system from further issues!