TIU with smoke showing, z750 the cause

I have never heard of an MTH Z-750 having that problem. Is the circuit breaker inside the Z-750 stuck? Both of my Z-1000's have hair trigger breakers, throws the breaker at the first hint of an overload, even if I try to put in too many powered units at once it throws the breaker.

 

I may have to watch my MTH Z-750 if that is the case, it powers the TIU base, while track one and two come off a 275 watt Lionel ZW.

 

Lee F.

If the smoke was coming out of the TIU, it wasn't the transformer that failed.

 

Something shorted in the TIU, placing a huge current demand on the Z-750...that's why it was hot.

George,

 Thankfully my TIU still works.

Are you saying that the TIU works with a different transformer? Where exactly was the smoke coming from, the TIU or the Z750?

You need to look for heat damage on the varnish of the board.  I have seen light smoke from boards that no longer work and the faulty component can not be found, but heavy smoke should have left signs of where the smoke came from.  Which is back to Barry's question of where did the smoke actually come from.  G

Barry, it works perfectly! You remember back around Christmas I had a similar issue with the other Rev H TIU . At that time I was Powering it with the same z750 transformer. I ended up just thinking I had a bad channel or blown fuse and ended up wiring both levels to fixed 1. About a month or so ago I bought the new Tiu and it has worked fine. Today was first day I actually ran trains the way I originally had it. That is a separate z750 for each channel. Not thinking about the past , I hooked the "problem" z750 to fixed 2. Something's not right with it. 3 hours later and the transformer is still warm to the touch. Hey but the trains are running!

George,

 

One more time...

 

Are you saying that TIU channel Fixed #2 still works fine with a different transformer? Where exactly was the smoke coming from, the TIU or the Z750?

Where exactly was the smoke coming from, the TIU or the Z750?

It was coming up from the vents in the TIU. I opened and there does not appear to be any damage. There is definitely an electrical smell to it. Yes the fixed channel 2 works fine.