TIU Not Responding

May just be the fuse in the TIU.  Am sure others will post with their thoughts, but I would start with the easiest solution.

 Does the red LED on top of the tiu light up when power is first applied??. It should actually blink and then stay on steady. The number of blinks is the actual TIU number.

no lights at all greg when power is applied..

As George mentioned.... Probably an internal Tiu fuse or  power supply breaker? If the power supply is OK you'll have to open the tiu. 6 screws on bottom, it's not too hard and much easier than opening the remote.

we are talking 2 second short on a passenger car wheel i'm new to dcs am I going to be opening this TIU every time I have any type of short??

Eric,

Your TIU isn't getting power.

First, check any transformer circuit breakers or external fuses to see if they've blown/tripped.

Otherwise, you'll ned to open up the TIU and replace the fuse on Fixed channel #1.

If it's not one of the above, you may have a serious problem.

In the future, you should have either external circuit breakers or fuses, or use a modern transformer with a fast-acting circuit breaker.

Wow I guess I'm going to have to do something I'm d*mn sure not going to open that TIU up every time I have a short.. I didn't think it would be that tempermental...

anyone happen to know what type and size of fuses the TIU takes??

Thanks guys I appreciate all the help as always.. anyone know the size of fuse that Ill need to be stocking up on??

Erie, it is a 20amp fuse. I got mine from my car dealer the day on my oil change no less.

Most likely if you see no red light when the current is on, then the fuse is blown in fixed 1 as Barry previously stated.. This happen to me sometime back. I also use an external power supply  from Radio Shack that plugs into the TIU.

standard blade type fuse you get at the auto parts store

Eric,

I didn't think it would be that tempermental...

It's not at all "temperamental".

If you don't have a fuse in the circuit and there's a derailment, you'll quite possibly damage equipment, including the TIU, your engine and, quite possibly, your transformer itself.

That's not anything related to DCS, rather, that's just physics.

I hear you Barry.. This new electronic stuff just takes some getting used to I guess.. I'm still old school... My postwar Lionel stuff welded itself to the rails hundreds of times over the last 5 decades during derailments without ever blowing a fuse or damaging anything.. This electronic stuff is a whole new world to me after 45+ years of running postwar trains. There is no doubt I think the new stuff is cool.. but if it turns out to be nothing but aggravation... NOOOO problem ill just go back to enjoying my postwar.. only time will tell!! Thank you again for all your help.. I'm going to add some fuses or breakers and see what happens... LOL!!

Erie Lackawanna...hang in there. Many of us run TIU's for months or more without blowing a fuse; and with many derailments. It's a very solid system. You just hit the perfect storm so to speak.

It is important to have adequate fusing outside of the TIU for sure.  

Thanks Jeff Im not throwing in the towel just yet.. I'm sure its a solid system.. Just frustrating.. The first one I got was DOA right out of the box returned it for a new one and now one day later this.. The more technical stuff gets the more problems your bound to have.. I have a 1965 GTO convertible in my garage that runs better with less problems than my 2013 Silverado.. That's just the way it is I guess..

Does anyone know exactly what the external power supply on the TIU does other than the obvious supplying power that is!! In other words what is the benefit to using one??

Barry's Book the DCS O Gauge Companion explains that since the TIU is a small computer, providing external power to it allows the TIU and all of its output channels to continue to function if power is lost from a power supply that is attached to a fixed or variable input, as you have yours now configured (Pages 92-93 of his book).

The fuse is a 20 amp mini fuse (two bladed with a fusible link between the bladed, yellow in color for standardization).  There are 4 inside of the TIU, and if you are not using the Variable channels right now, you can remove one and insert it into the Fixed one slot to replace a blown fuse if you find it failed.

I had my first TIU installed for less than one hour before a simple derailment blew the fixed channel one fuse.  I was surprised.  The 6 amp breaker on the MTH Z1000 power supply didn't trip, but a 20 amp fuse failed.  I now have a box of 25 of the 20 amp fuses from Autozone.

On my second derailment the 6 amp breaker on the power supply did trip, leading me to wonder about the integrity of the fuse that failed.

Rick

Very interesting Rick thank you for the info..

We blow fuses the odd time but we used 10 amp  32 volt fast blow (glass) between the power supply and each tiu input  channel....We 're still using an original tiu from about 2002(G version)

A post war ZW will destroy a tiu in short order without the additional fuses.... easy to change

Greg your using the 10 volt glass fuses between the ZW and the TIU what about on the output (track side) ?? That's what I'm running postwar ZWs  Do I need to fuse both sides of the TIU seems like a lot of fuses to me!! LOL!!

Nope just on the input side... Think of the power supply as a big sledge hammer, If there's a short on the layout (track side) the surge of power has to go through the tiu. If the fuse is on the input side,the surge has to go the fuse first (between  power & tiu) and of course blows before getting to the tiu. (hopefully)

It would be best to use a fast blow 10amp fuse between TIU and transformer.  The 20amp fuse inside the TIU will protect the TIU from trace damage.

You can move a fuse from one of the Var channels not being used to restore fixed 1 and see if that powers up the TIU.  Folks also use TVS to protect against voltage spikes.  These could be placed between the track and TIU output.  G

Ok replaced the 20a mini fuse @ imput 1 inside the TIU and added a 10A  between the ZW and the TIU and all seems to be working fine..  This forum is awesome where else can you get so much information so quickly and from so many people that actually know what they are talking about.. It gets no better than that!!  Thanks to EVERYONE for the help.. Gotta pick up a copy of Barry's book to refer to also.. Happy New Year to all!!

Folks also use TVS to protect against voltage spikes.  These could be placed between the track and TIU output.

The TIU has TVS's built-into each channel's circuit.

That was my thought as well. Like mine, you hear many people blowing that factory fuse early in the life of their new DCS system. Once the fuse is replaced, you don't hear many follow ups about it blowing again. I've had many breaker kicks on my brick since replacing that factory blade fuse, but that fuse hasn't blown once. 

Barry I know, so do the MTH transformer controllers.  I said Folks like too....   G

As mentioned earlier here is a picture of my fuse protection. Some days I'll blow three fuses and then go a week without a blown fuse.  I don't have derailments form running the trains,  My yard line which is separately blocked has the coal loader and uncoupling track.  The kids knock the trains into a short situation and any time we have the yard line powered up buy accident - pop goes a fuse.  The uncoupling track is powered with a different transformer so the kids can use it without power to the main track,

thanks for posting the pics TMACK

I guess I need help, too.  My older TIU quit working, so following advice on the Forum, took the shell off the circuity, looking for a fuse.  I don't see a fuse that looks like the 20-amp in our car.  What am I looking for?

The original tiu from 2002(version "G")  is not fused . I don't think there's even a version number on the bottom. (if I remember correctly) 

What's wrong with it??

Gregg,

The original tiu from 2002(version "G")  is not fused . I don't think there's even a version number on the bottom. (if I remember correctly) 

You remember correctly!

Yes, What are the symptoms?  Does the Red LED blink and then stay on?  G

Besides Barry's book, which I bought in its first edition, I also found this site helpful:

http://www.toytrains1.com/DCS_Tips.htm

As a beginner, I had to do a lot of reading up prior to setting on the track and go. Not only can you blow fuses in the TIU, but the electronics in your train may get scrambled. It is best to be highly protected.

Here is another helpful read, most submitted by forum members. http://www.jcstudiosinc.com/Bl...=486&categoryId=

Coming here and asking questions is definitely the right thing to do!

Rick

Gentlemen,

   I would suggest an upgrade in TIU even if it can be repaired.  I also recommend

Scott 10 Amp Breakers rather than fuses, IMO they are much easier to use and easily reset.  I used them between my TIU's and ZW's & KW for 10 years, the Z4K has it's own breakers.  The OGR Video Guide to DCS is another good educational purchase.

Being able to watch the video for reference as you build your DCS layout is great for hands on learning, along with Barry DCS O Gauge Companion Vol #2 for hard reference instructions, there is just about everything required for building a DCS layout.  When purchasing a DCS you want to make sure you purchase the latest TIU revision, older units like this one that has no fuse and old technology are something you want to avoid when purchasing your initial unit.

PCRR/Dave

Pull the board out of the case and look at the bottom of it.  See if you see a burned trace.  That usually indicates a failure that MTH won't fix, we had one at the club with that same failure.  It still has three channels, so I use it that way.

Erie Lack,

   gunrunnerjohn is right, even damaged you still have partial use of your TIU, use the Scott Breakers to protect the rest of your TIU.  If your TIU has a fuse take the TIU apart, find and replace the fuse.  Long ago when DCS 1st came out, Barry saved me from running my TIU without the 10 Amp Breakers, I had blown an internal TIU fuse and had no idea why, this was back in the early days before Barry had written his book or Rich had made the OGR Video Guide to DCS.  Barry's advise saved me a lot of frustration, his book is outstanding, purchase it and learn from it.  Purchase the OGR Video guide also, Rich does a great job explaining visually how to set up your DCS, especially with the old ZW & KW type transformers.

PCRR/Dave

The biggest issue with Barry's book? 

There's just so much stuff there it takes a ton of reading to get through all of it!

gunrunner,

   Oh yea, what an educational piece of material that takes a little while to digest. This is why I also recommend the OGR Video Guide to DCS, although not as complete as Barry's book, it's an immediate reviewable instructional video, that an owner can use while building his layout, not as complete as Barry's book but a darn good DCS educational video.

PCRR/Dave