Problem with MTH PS2 U50C-Solved

Tried something that worked.  Moved the input and output on the TIU from fixed 2 to variable 2 and that seems to work fine.  Engine performs normally.   Then I did a factory reset on reset on the TIU and tried Fixed 2 again but that did not change anything.  Variable 2 still works.

Is there a fix for Fixed 2, or has it gone bad?

If this is a Rev. L TIU, a common issue is the DCS signal driver chip loses drive.  It's a chip that can be replaced.  It's a surface mount chip, so you do need some soldering skills to remove the old one and replace it.  I stock the necessary chips.

Your symptom contradict.  Do other engine work on Fix 2?  Each TIU channel is separate, so just because engines work fine on F1 or V2, does not mean they work on F2 as example.

Engine is part of system and each can perform slightly differently track signal wise.  But if engine works on a channel fine along with other engine, then the engine is good.  If an engine does not work on a specific channel, but others do work on that same channel the engine is most likely at fault.

Also make sure track and wheels are clean.  Both effect DCS signal.  Including pickups.  G

I am still trying to determine exactly what is going on.  Now, nothing is working on Fixed 2 or Variable 2.  But fixed one works. Going to try a couple of other things but I suspect this TIU may have seen better days.  Is a repair worth it or should I just replace it?   It is the original TIU with the RS232 port.

After further testing, here is what I found out.  I put 4 different MTH engines on Fixed 1.  3 are PS2 and one is PS3.  A read found them all and they all started up and ran.  None of them work on Fiixed or Variable 2.

Tiu is repairable.  I do them. G

Send it to George, I suspect he'll be able to give you a quick turn-around.

Thanks for all the help.  Glad to know the TIU is repairable.  Finally found a solution with the help of a local train friend.  It was a wiring problem.  When I was updating some wiring, I did not do it correctly and wired directly to the track in addition to the TIU and that just did not work.  I have now wired it correctly and everything seems to be working now.  Thanks to everyone for their help.