HALP! Suddenly having issues with MRC PA...

[wm3798]

I know I know, the crow is cooked and ready to be eaten...
But seriously, I'm moving things around tonight to get ready for a few visitors tomorrow, and suddenly things stop working.

Here are the symptoms:
Locomotive addresses are not acquiring.  The readback says the address is right, but when dialed up, nothing happens.  When the decoder is reset to factory defaults, the engine works fine on 03, and even things like speed matching and momentum work.  Key in to set the address, it turns into a paper weight.

Consisting isn't working, but only on some lokies.  Key it in, read back CV19, everything looks fine, go to start it, nothing.  Others work fine, although the headlight thing is screwed up. (next item)

Headlight function isn't working right.  Acquire the locomotive address, hit -0-, the headlight flashes for an instant, then nothing.  Doesn't work on individual engines or on consists.  This happens on engines that do operate with their normal address (unaffected by the address problem).

I'm completely stumped.  Tomorrow I'll start pulling things apart to try to isolate the problem.
My question is, are these symptomatic of a decoder getting zapped, or do you think there's something in the system that's screwed up?

Note:  There was a derailment that caused a short, but it was caught by the breaker pretty quickly.  Also, the first engines that I noticed malfunctioning occured before the short...

So, are these symptoms of DCC in general, or do you think it's an MRC-specific problem?  I'm worried that since the symptoms are occuring in some engines but not all, that a bunch of decoders have gone down.  I can't afford to replace them right now (or maybe ever!).

Any thoughts?
Lee

(And the first guy that whines that I should have gotten Digitrax gets socked in the mouth... I'm in no mood to hear it...)

[cv_acr]

(And the first guy that whines that I should have gotten Digitrax gets socked in the mouth... I'm in no mood to hear it...)

OK, you should have got NCE. 

[Ryan87]

Do the locomotives not working have anything in common? (Same decoder?)
Are all locomotives effected? (either addressing or headlight) or do some work fine?

[John]

hook the thing up to a simple piece of flex trak .. nothing else .. and lets go from there

[wm3798]

Well, I pulled the plug on the layout, and hooked up the main wires to a single piece of track.
I got track power, but nothing else. 
I then plugged in the main to a regular DC pack and ran a regular engine around... no problems there.  I did isolate the yard area, because that's where all the DCC engines were.  It could be possible that the problem may be over there, but there's evidence to the contrary.  The running lights on the turntable operate off of track power, and they were lit when the yard was connected, with no sign of a short anywhere.  Also, I had been able to operate trains in and out of the yard last night.

So, I guess I pack up the control module and send it back to the factory...

I need to take some engines down to the club to confirm that the problem isn't in the decoders.  This morning's tests left EVERYTHING not working, including an engine I just put a decoder in and had tested just fine about a week ago, but wasn't on the layout at all again until this morning.  This tells me something's up with the system, but until I can re-test the engines on another layout, it remains a mystery.

Lee

[John]

Lee .. its unfortunate you don't have the ability to check programming with something like JMRI ..

[Iain]

Is there a battery you can pull out of the MRC box for a few minutes to try a hardware reset?

[John]

It almost sounds like you screwed up the programming on all your engines .. and now none of them will accept the programming from the MRC. Is there anyone over that way that has a DCC setup with a programming track that you can read all the CVs on?

[wm3798]

I can read back the all CV's with the MRC... Everything looks normal, that's what confounds me.  I've been checking the ones that I know to check, 29, 19 (advanced consisting), but it would be helpful if Digitrax included a comprehensive list of settings with their decoders the way NCE does...

I'm assuming that when I hit 8-8 to reset the decoder to factory defaults, that the only CV's I need to read are 29 and 19, other than the address.  As such, everything is reading back just fine, but it's not getting through the head of the system.

I'll fool around with it some more tonight.  But for now, I have to get some work done.  Carhart's got the same system I've got, he's going to bring his control module down one night this week which should confirm whether it's the decoders or the system.

As I said, I strongly suspect it's the system, due to the fact that engines that haven't been on the layout in a month or more are not acquiring.  They couldn't have gotten zapped, unless it's occurring the instant I put them on the rail...

Lee

[Skip]

Lee,

Is there a way to reset the command station?  I am only familiar with Digitrax, but over the years I have had to do a complete reset to clear some strange problems.  Also, as Iain mentioned, is there a battery?  The Digitrax system has an internal battery that will cause some weird problems if it goes dead.

Sorry I can't be of more help
 

[wm3798]

I did some more experimenting tonight, and the main problems appear to be memory related, so I can't help but wonder if there isn't a battery in there.  I don't see an obvious port for one, and I haven't read that part of the manual yet...

After I shut it down, then turn it back on, the last consist to run won't re-capture... at least not right away.  According to the read back, all the CV's are where they're supposed to be, so there's not a decoder problem.  After I reset the engines and re-program the consist, it seems to be all right... with the exception of the headlight... sometimes.

Some of the headlights work fine.. the Atlas Lenz boards have no problem lighting up, but the blinking problem occurs on Digitrax and NCE chips.  Again, intermittently.  99 percent of the time, the headlight is dark, and when -0- is pushed you get a little blink, then dark again, even though the display indicates the lights should be on.  However, after running some engines for about 20 minutes, I called them up on throttle, pushed -0- to see what would happen, and lo and behold, let there be light!  It worked on several of them, so again, I don't think it's a decoder or programming problem.  Something isn't getting communicated from the hand held to the chip.

Anyway, I figured out that if I drop the address of the consists on the layout from the throttle before shutting down, they stay active.  So alas, I can run trains for the moment.  Later this week I hope to test my decoders and throttles by borrowing another PA command station.  If everything runs without a hitch with the new one, then I'll know immediately where the problem is, and said problem will be parcel posted back to MRC for repair or replacement.

Think they'll provide me with a new PA-2?

Lee

[amato1969]

Like you say, running with a different command station will tell you for sure.  Is your unit still in warranty?

[wm3798]

I doubt it... It's been up there for at least two years now.  I'll have to look it up.
Lee

[John]

Update?

[wm3798]

Brian lent me his command station.  When I catch my breath with work, I'll do some more testing.

Lee