E-STOP on remote was used and engines are no longer recognized or can be added

What do you get when you press the read button?

Try it tethered?

Is the TIU on? You can get power through even with it off.

Did you go in and make sure that DCS is enabled on all tracks?

• MENU
• SYSTEM
• DCS SETUP
• Press AON

@John H posted:

Is the TIU on? You can get power through even with it off.

I didn't even catch that. The TIU light should be on! and count the blinks on power up to make sure the address is correct.

Thanks for replies so fast.  When I hit 'READ', the readout stated ...

'READING TRACK - Searching Engines ... please wait' ... Then display stated 'Found TIU Addr 1 with 0 AIU boxes connected ... Then it showed NO ACTIVE DCS ENGINES.  I haven't tried it tethered yet, but can certainly try and report back.

The TIU is ON as evidenced by the red led lit in the one corner of it.  It appears I'm just not getting the DCS signals to work either properly or at all, which is a separate component that 'rides' on the track voltage, which I do have at 22 vac.  I may have to use a scope to look for DCS signals, but was hoping for an easy fix.

Finally, I did go into the menu and selected 'AON', but that didn't resolve my issue.

Because my TIU rev. is L, I believe the following a post is the cause and fix, but will certainly try any other suggestions before performing surgery.  Thanks again for your quick replies and looking forward to your thoughts on other remedies as well as the post that I found.

It's great that it found the TIU. Always start with the basics.

Seems like you covered several when you swapped out remotes and TIUs. Although you used the E stop for some reason, what happened right before might lead to what's wrong here.

Do you have proper protection between the TIU and the transformer?

Can you power the TIU from AUX power or fixed in 1.  Then try running the trains through fixed 2 in and out.  Maybe only fixed 1 is losing DCS signal.

The driver failures described in your linked thread are usually due to transients, but rarely all the channels.

You swapped out TIU's & tried different remotes. You mentioned it's not recognizing any engines. Are you getting a message, "Engine Not Found", or similar message? Can you isolate the TIU to an independent section of track with a power source, do a track read, delete an engine from the remote & re-try adding that engine?

Sorry I forgot to mention why I used E-STOP ... I used it because there were about 3 episodes where the train for some reason would no longer accept some commands from the remote (like throttle response, bell, whistle), so I just figured that was an acceptable method to stop the train under those circumstances.  After all the function was supposedly designed into MTH DCS by MTH.?

I did power the TIU via the AUX port just fine - red LED blinked once indicating Addr #1.  Then fed fixed 20 vac into 'FIXED 2IN'.  And wouldn't you know - I was able to control the train great, powering the track from 'FIXED 2OUT'.  Thanks for that great idea!  Additionally, I did try using the DCS Fixed1 and Out1 with it powered via AUX separately and it still does not work - won't recognize engine.

So it appears that I've only lost one channel.  But seeing the data in the post that I put above, it sounds like I need to do surgery on Channel FIXED1 and may also need it on FIXED2 channel possibly as time moves on - as the data showed in the spreadsheet in the post above.  It was a brand new TIU after all that came in a WIU/TIU boxed kit.  I had powered the TIU off and on by removing power from the DCS FIXED1 in during several days before Christmas, and all worked fine - at least the first few days.  I read in the DCS book that TIU AUX in power isn't required and DCS FIXED1 in could be used to power both the TIU and track DCS FIXED1.  I probably didn't realize the channel was going bad, except for the 2-3 times I began loosing control of the engine (no remote buttons were working such as throttle, whistle, bell); then using E-STOP to halt the engine.  I was able to use that method a few times, but after the last time apparently the DCS signal amplitude was so low that it would not even recognize engines.  So, I am thinking all Rev. L TIU should get mod'ed, as it's a bad design as the linked post above indicated with 5 brand new Rev L TIUs.  At least that is my thinking and of course welcome any other knowledge, ideas, and opinions about my issue.  Thanks to all that have responded to my quest for help!  I had no idea any problems existed and thought with the latest rev I should be fine.  Lastly, although the latest rev L TIU does incorporate internal fuses for protection for major track faults, I do use 10A fuses on both in's and out's of my TIU.

It's OK to use the E stop.

What the issue here is, is why you lost control in the first place before you used it. It sounds like something knocked out TIU fixed channel #1.

So before it happens again, you may need protection inserted between your power and the TIU!

I use a simple 10 amp auto blade fuse and holder that are even available at Walmart. I have it on each power supply at each TIU input.

What is your power source?

BTW, I've had some of my TIUs last over ten years and never had to have any of them repaired ( 4).

@Chewy posted:

fine.  Lastly, although the latest rev L TIU does incorporate internal fuses for protection for major track faults, I do use 10A fuses on both in's and out's of my TIU.

Joe, he already has that and more.

So what kind and size of fuses? Why on the in and out?

Joe, you must be giddy from last night's Bills game.

, I do use 10A fuses on both in's and out's of my TIU.

Go Bills! some more!

@John H posted:

Joe, you must be giddy from last night's Bills game.

, I do use 10A fuses on both in's and out's of my TIU.

Go Bills! some more!

Yeap! soury

Although I do use MTH power blocks and MTH Z-4000s, I still fuse both sides using 10A 'bladed' fuses as per direction in the MTH DCS (Digital Command System) Operators Manual - 5th ed.  

"MTH therefore recommends that any user employing an older transformer that does not meet today’s U.L. standards install inline fuses or circuit breakers between the transformer and the TIU input channels. An AG3C “fast-acting” or “fast-blow” fuse rated at 15 amps would be suitable protection. These can be obtained from most hardware or electronic stores including Radio Shack. Users will also need an inline fuse holder to house the fuse. Radio Shack sells a heavy duty model, part number 27-1217.I thought I remembered reading about doing that in the book that could be purchased that was written about DCS"

Additionally, the DCS Companion v3 book also discusses fuses.

I started using fuses after I had an earlier rev TIU go belly up - the red LED blinked 15 times during power up.  It wasn't worth getting fixed, although I still have it.  I may find and answer to fixing it someday.  That particular TIU rev did not have the internal fuses as the later revisions now do.