TIU not seeing AIU

Some of the cables shipped with the AIU's were bad   Some had straight through wiring and some had the connectors loosely crimped   If you have a crimp tool you can squeeze them again to make sure the crimps are good 

This is an older thread about the cables

https://ogrforum.com/...-trains-tiu-aiu-cord

The first thing to check is the cable. As Ben states MTH did ship some that were incorrectly assembled, but that was quite a while ago. Most should be out of circulation by now. If you lay the cable out flat, both connecting tabs should be up or both should be down. If your cable has one tab up, and one tab down, then it is bad.

Second, presuming the cable is good, and connected to the correct ports, apply power to the TIU. The red light should come on and flash the number of the TIU address. Turn on your remote. Hit the <READ> button. The remote should find and show both the TIU and AIU. If only the TIU is found, then either the cable is bad, or the AIU has a problem. You can find replacement cables on the 'net. Look for  RJ12 6P6C Reverse Wired Cable They are not expensive. Trouble shooting the AIU is a PITA. BTDT!

Chris

LVHR

@Tugboat15 posted:

I found one post about powering TIU with a wall wart and also powering the AIU.

This can be taken 2 different ways IMO.  If you are suggesting that the AIU needs to be powered the answer is no, it can't be powered.  Any power that it needs it gets thru the TIU via the cable.

I hope that I didn't insult your knowledge with my comment.

- walt

Lehighline... I did run across your lengthy troubleshooting post when trying to get a few AIUs to work.

Cable that came with the AIU, both tabs face same way. I even bought another one to see if it was the cable. Now I want to see if I'm getting  voltage from TIU, through the cord to AIU. I'll have to find that post and see which wires I should see voltage.

Then as another test, took TIU down, plugged in wall wart to aux, and cord to AIU. No dice.

Your good Walt. I understand AIU does not need its own power supply. Gets juice via the cable from TIU. Posts I  read is most setups were in passive mode and power TIU via Aux port. So I tried that as well.

Only have 1 TIU which is seen, but get "no AIUs connected".

Aight... who lives in Texas, or nearby lol. I'll take a road trip to see a layout and test my equipment.

Lehighline, when you opened up the AIU, could you see what chips were actually bad? That was my next step. See if something let out the magic smoke.

Only way I can troubleshoot further is to buy a new AIU, visit someone, or find repair house willing to take a peek.

For what its worth. I was in the process of taking TIU down and boxing it up. I never unplugged the WIU from the TIU. I read that this was not enough juice to power the TIU and then AIU. Well after unplugging WIU, hooking up AIU to TIU, and then applying power to aux, it now sees the AIU. I pulled apart and connected several times to make sure I was not seeing things and it was not a 1 time fluke.  Finish wiring my last to switches, and then hopefully start using tablet to control everything.

@Tugboat15 posted:

Your good Walt. I understand AIU does not need its own power supply. Gets juice via the cable from TIU. Posts I  read is most setups were in passive mode and power TIU via Aux port. So I tried that as well.

That's only partially true.  It may be necessary to add aux power to the cable between the TIU and AIU's if you have multiple AIU's.  It's not needed for only one AIU as a rule.

@gunrunnerjohn  I have never heard nor read of that John.  How does one bump up the power that operates the AIU?

as always, thanks - walt

I saw that post as well. Took me a bit, but found it. For me, only one TIU , and AIU, and the AIU sits under the TIU. Not far away from each other.  This is pointing at AIUs, or multiples, spread far apart and voltage sag. Almost like adding drops from a bus wire, so they all see the 12v source voltage.    https://ogrforum.com/topic/cannot-find-aius

Got my 5 switches wired up and set to the AIU. Had to fix a few wires to match the throw icon on the tablet. If I throw one of them too quickly from one direction to the other, it does not fully throw. It is a new Ross, so will see after a break in period. My only other thought for down the road is adding a capacitor to help out. I see it gives the ability to throw multiple switches at the same time per a route. Hopefully something ill get to play with soon.

And yep, I need to move way up north east as large scale layouts and the support is just not here where I am. LHS few hours drive for me is heavily into N scale with a layout. Another store full of G scale, but no one works the train department.

Lehighline, when you opened up the AIU, could you see what chips were actually bad? That was my next step. See if something let out the magic smoke.

With my AUIs the answer is "No visual". What you do is feel for heat. The chips are cold or cool when operating normally. A hot one (or more) is a problem child.

Chris

LVHR