Skip to main content

Several months ago I asked the forum about my MTH DCS Explorer that stopped working. Fuse was good, but no MTH WiFi out and no 14.2v digital package out. Track light inop. I have always been able to read that digital package on the little Multimeter (DC setting) I have.

After several responses from forum members I bought another 50-1035. My Z-1000 is putting out 19.6vac to the Explorer (no load as read on my multimeter). My six MTH left and right switches are on the 14vac aux out of the Z-1000 and have worked fine, and are still working fine, at all times. My accessories are on completely separate power sources.

I recently connected my new DCS Explorer without load. Had MTH WiFi out and DCC package was good at 14.2v on my DC voltmeter setting. Then I added the barrel wires and the digital package was good at the end of those. Then I plugged in the the track interlock (not connected to the track) and the digital pack was good coming out of those prongs, but the track light on the interlock did not light up. I tested several interlocks and the power continued through them without track connection. I then connected the track interlock, with tracks complexly empty. Still no track light and my new MTH Explorer slowing lost the digital package power. I pulled it quickly from the tracks and measured it dying from digital pack 14v to 10v to 6v to 2v and dead. MTH WiFi out died with it. Fuse never blew.

So right now I do not have an interface unit and have been checking my track. I cannot find any shorts; each track has continuity section to section and the three tracks are open to each other. Engines were never placed on track with this newest Explorer.

At a loss at this point. Any thoughts on my power problems. This all worked wonderfully until three months ago when my first Explorer went out without blowing a fuse. The fuse is still good on the new Explorer also.

Original Post

Replies sorted oldest to newest

Taking a wild guess here: any chance that just before the first Explorer failure you added a bunch of TVS diodes or anything else which may have significantly decreased the track circuit impedance at the DCC frequency range of 8-10kHz?  This wouldn't necessarily be evident with a DC resistance check, but may be evident with a capacitance check.

Last edited by SteveH

Steve,

Thanks for the response. I have not added anything to the tracks or power lines. Also, do not have an ability to test capacitance. I can test AC, DC DCC, and resistance. As in my Air Force electronic days (1969-1979) when I worked on tubes, real capacitors, and real resisters with colored lines on them, I think I need to go back to: "what was the last thing I did to any tracks." That being - I have been working on a highway crossing across/overlapping two 0-31 curve sections. I was working on wood plus neoprene cut out layers to fit inside the rails. Had not gotten to outside road leveling up to the rails.  My only thought is to start there and then pull every section of track and test them. Can't afford to eat up anymore TIUs with or without WIU. PS: I left the electronics repair world while transistors were exciting and integrated circuitry was two layers of a board. I had to teach myself all my layout wiring and using a multimeter again when I started playing with my train in 2017. Note: I do have some glued-on mini-rock walking paths and some ground foliage up close to the outer rails, but the trains all worked fine with those and all my other walking path/road crossing for months.

@Lee @Omaha It may be easier and faster than starting by tearing out track to buy a multimeter with a built-in capacitance check.  They're pretty common these days and even an inexpensive one would give you a good idea if track circuit capacitance may be in play here.

Here's a sample of available meters that would do the job:

https://www.google.com/search?...&sclient=gws-wiz

Last edited by SteveH

OK. Thanks again. I've taken a look at my 20+ year old multimeter and, besides a DC 1,000 Max Volt and AC 750 Max Volt it has a Diode Checker, a K-Ohm, and a DCmA setting. I just downloaded a Capacitance 101 refresher and am reading about checking all or nothing capacitance with a Ohmmeter. I assume I am looking for a capacitance (charge and discharge between my rails? Is that the process you are recommending?

@gunrunnerjohn Something has apparently killed 2 different Explorer's DCC and their Wifi signals upon hooking up to the track (see link to previous Topic from OP).  If I understood correctly both are now dead in this regard when disconnected.  I'm not sure what else could be the cause of losing the pulsed DCC output and Wifi at the same time.

@Lee @Omaha can you clarify that both Explorer units are not putting out DCS and Wifi when disconnected from the main track?

Well, connecting to the track shouldn't kill them unless something else providing power is connected to the track!  Shorting the track leads shouldn't kill them or they'd die at the first derailment.

That being the case, my approach is to simplify what you're testing and find out what works and doesn't work.  If power isn't coming through the explorer box, it's clearly something internal to the box.  If the internal fuse isn't blown, it's hard to imagine what is going on.

Well, connecting to the track shouldn't kill them unless something else providing power is connected to the track!  Shorting the track leads shouldn't kill them or they'd die at the first derailment.

That being the case, my approach is to simplify what you're testing and find out what works and doesn't work.  If power isn't coming through the explorer box, it's clearly something internal to the box.  If the internal fuse isn't blown, it's hard to imagine what is going on.

At this point yes, there's would seem to be something internal that died in both Explorers, the one he had originally and the one he bought to replace it.

My thinking is: what would cause both units to fail identically in these ways.  I don't know exactly.  What do the 8-10KHz DCC pulsed waveform and WiFi both have in common, they are at much higher frequencies than 60Hz, maybe different amplifier or oscillator circuits?, different part of the power supply?, not enough current at these higher frequencies to blow the fuse, but enough to overdrive part of one or more circuits?

Beyond this, I don't know what else to consider except that something, when connected to the track circuit, seems to be causing the Explorer to overload at high frequencies only.  If no other power sources are connected, what else could cause this phenomenon?  That's why I think a capacitance check wouldn't be a bad idea, even if unlikely.

Considering all the tests Lee has previously detailed above and his 10 years of electronics experience in the Air Force, how would you propose that he might test to see what works if the units no longer function correctly in either case, connected to or disconnected from the track?

Last edited by SteveH

Well, I'd first figure out what is connected to the track that would be providing power, other than the DCS Explorer!  If the track doesn't have any other power source, I can't imagine how connecting to it would blow up the Explorer!

I'm not sure where 5-10khz and DCC come into the picture, the description is connecting a transformer to the input of the DCS Explorer and connecting the output to the track.

Well I feel a bit stupid now   The OP mentioned"Had MTH WiFi out and DCC package was good at 14.2v on my DC voltmeter setting...)

Not being very familiar with the MTH Explorer, I inferred that it has DCC and DCS control (like some MTH Locomotives do).  At first, I didn't want to respond at all, but after a while there were no replies to the original question, so I thought I'd just offer a "wild guess" in the hope of getting someone more knowledgeable about the Explorer to jump in and help.  I guess maybe that's something.

At this point, I'm going to take a step back and let the experts continue to ponder this mystery.  Thank you for your assistance.

Last edited by SteveH

The DCS explorer never output DCC, it's strictly a DCS device.   The box has to be configured and connected to pass power, I'm questioning if there's really anything wrong with the Explorers.  Do you get any indication when you connect power to the inputs?  You should get at least the power light.

If you don't even get a power light, I'd suggest you start by sending the two DCS Explorers to an MTH repair facility and find out what happened to them.

gunrunnerjohn,
just a note. You can measure a DCC digital 1s and 0s packet using a DC voltmeter (see below). For instance, my two DCS Explorers both gave a +14.2 DC volt representation, inside track to center track, and a -14.2v measurement from outside track to center. I could also measure those directly from the barrel jack out of the Explorer with my DC voltmeter showing a positive and negative depending on if my red or black lead was in the center of the barrel and the other lead on the outside of the barrel. First DCS lasted 3+ years, second one lasted about 3-minutes.

This is the measurement I was making on my new MTH DCS while watching it die from 14.2 to 10 to 6 to 4 to nothing. $179.00 out the window. The track light on the newest DCS lit initially, stayed lit when I hooked up the track lockon and then slowly died away when I plugged into the track – no engines or cars on the track.

“An accurate measurement can be made on some DCC systems by using a DC voltmeter. Connect one lead to either track and the other lead to the “earth screw” on the booster. This will show ½ the DCC volts. Multiply by two and this is your DCC track voltage. Not all systems have this ‘case’ connection. Use this method or a specialist DCC meter to adjust, if possible, the DCC system track voltage.” http://www.members.optusnet.co...swmn2/DCC_Meters.htm

Several new questions for anyone.

  1. Several new questions for anyone.

    1. Is there anything such as an MTH help email or help phone number anymore?


    1. After looking and looking online and finding nothing, does anyone know the voltage tolerance out the Z-1000 brick. Is it 18V +/- something, or is the 19.6v I have out of my Z-1000 a transformer problem and not that much should have gone into an MTH DCS?


    1. What do people think about me getting an MTH ZController and trying analog to test the track?
@Lee @Omaha posted:

gunrunnerjohn,
just a note. You can measure a DCC digital 1s and 0s packet using a DC voltmeter (see below). For instance,

Lee, you're confusing DCC with DCS, apples and oranges!  The DCC signal is the track voltage, the DCS signal is an RF signal that rides on the AC track power.  You will most certainly NOT be able to detect or measure the DCS track signal with a DC voltmeter!

  1. Is there anything such as an MTH help email or help phone number anymore?

1. Not as near as I can detect, you're best bet is probably right here in the forum.

  1. After looking and looking online and finding nothing, does anyone know the voltage tolerance out the Z-1000 brick. Is it 18V +/- something, or is the 19.6v I have out of my Z-1000 a transformer problem and not that much should have gone into an MTH DCS?

2. The Z-1000 bricks have had several generations, I believe the first one put out as much as 24V, then there was one at around 21V.  I believe the current one puts out between 18-19 volts.

  1. What do people think about me getting an MTH ZController and trying analog to test the track?

3. I have no idea what you hope to accomplish with this test.  See the previous conversation about the nature of the DCS track signal.

Add Reply

Post
OGR Publishing, Inc., 1310 Eastside Centre Ct, Suite 6, Mountain Home, AR 72653
330-757-3020

www.ogaugerr.com
×
×
×
×
Link copied to your clipboard.
×
×