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General Troubleshooting Tips

For troubleshooting tips on a specific aspect of DCC, see that particular section.


This is the most important troubleshooting tip I can give you.  This is absolutely essential.  Remember this now, because you won't want to believe it when you have a problem.  You must be able to keep thinking rationally.  If you have to, pull a Gomez Addams and blow up a train — make it a brass one if you have to.  You must lose that frustration and be completely calm.

Also, don't panic.  Again, calm down.  Try to imagine it's someone else's $50 decoder that is smoking.  Use a fan to quickly blow the smoke away.  This will make the smoke harder to see so maybe you won't notice it — or smell it.

By the way, if you let the smoke out of something, it won't work anymore — ask any electronics technician.

So is all this hard to do?  You bet; it certainly can be.  I can tell you it's no fun when you get called in at 3am.  Managers definitely aren't happy when the down equipment is costing the company $10,000 an hour in lost production.  You can do it — even if it's a big train show!  Rushing and trying to skip steps when you would be calmer isn't going to fix things faster.  Chances are, it will make things worse as you make mistakes you wouldn't otherwise make.  Relax!

TROUBLESHOOTING D:2  Think of ALL the Possible Causes.

Too often I see people think the problem is the first thing that pops into their head.  Then they try hard to fix this problem — which may not be the problem at all.

You don't have to think of every single possible cause, but the more you do, the better.  Try to think of 3 or 4 before you start.  In any event, be open to possibilities you haven't yet thought about.

Real Life Example:

Turn on a ceiling fan that has a light.  The light isn't working.  What could be wrong?

- The bulb is burned out.
- The switch is bad.
- The circuit breaker is tripped.
- A wire is loose.

Does that do it?    Nope!  What about the pull chain on the fan's light fixture you rarely use?


What do you know as absolute and undisputable fact?  Are you sure?  Be sure you are not assuming something as fact.  I've seen this get a lot of people get into trouble assuming something.

Real Life Example:

You think that a connector might be bad.  You ohm out the pins on both mating parts of the connector.  All check and you go onto something else.  But do all the pins mate when the two are pushed together?

What do you know for fact should be your only basis for assessing  the working components of a problem.  Until you have tested the connector mated, the fact that it is good should remain suspect.  Knowing things for fact helps narrow the prospect for the problem.

TROUBLESHOOTING D:4  What Don't You Know?

This is a very important list, too.  Your goal should be to eliminate those things you don't know for fact.  Turn them into fact — be it good or bad.


If this all sounds like too much trouble, I guarantee it isn't.  I have seen people spend countless hours trying to solve a problem — people who were familiar with the equipment.  I am asked to help out on a machine I have never looked at before and fix the problem in 15 minutes.  Am I a brain?  No, and I absolutely hate fixing things.  They are frustrated and probably failed to do one or more of the above.  The first thing I do is take a deep breath and look broadly over the situation.  During the broad overlook, I usually pick up something that was missed by being too focused too soon.  We are talking simple things like blown fuses, bad sensors, and the worst one, loose wires.  See the next tip on loose wires.

TROUBLESHOOTING D:5  Tug on Your Wires

Especially when using any kind of screw terminal, tug on your wires hard enough that they will come loose if you don't have a firm connection.  Not a tug-of-war pull, but an honest pull that will reveal a bad connection now, not later.  Tug on soldered connections, too, especially if you are not a good solderer yet where you may have cold solder joints.

Do not tug on decoder wires!  Unfortunately, you can't really tug much on any of these really small wires.  But on your bus and feeders, do it!

TROUBLESHOOTING D:6  Divide and Conquer aka the Binary Search.

Track Wiring #5-21 contains a good discussion on localizing a short.

Isolate Your Problem(s) When Nothing Seems to Work.

If you are like most modelers, you do a lot of wiring before you test anything. Then you turn on your system and nothing works. Your trains don't run. Your throttles don't even work. Panic sets in. You don't know where to start.

Chances are, you have more than one problem. It is virtually impossible to troubleshoot anything when you have more than one problem. You need to isolate pieces of your system so that you only have one problem at a time to address.

Start with your command station. Disconnect everything, including track wiring and your throttle network.

Now connect a single throttle to your command station. Does it seem to work?

If so, reconnect things a little bit at a time. Connect perhaps your throttle network. If things stop working, disconnect half of your throttle network. Continue disconnecting or reconnecting things a bit at a time until you find your problem.

With your track disconnected from your boosters, reconnect them one at a time. When all goes well, start reconnecting track a little at a time.

Whenever you have a problem that baffles you and you don't know where to start, isolate portions of your system as described above. If you haven't done a lot of wiring since you last tested things, you may only have to isolate the portion you added recently.

Whatever you, don't try to troubleshoot the system with everything connected. You never make any progress that way.



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