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I seem to have a blown TIU. Was checking MTH info on their website and its most likely a bad fuse or at least that is where I plan to start.

Has anyone out there replaced one. If so are there any pit falls I should look out for or is it pretty straight forward?

Looks like its a 20 amp yellow auto fuse and they show four screws to be removed. If it matters its a REV.H1.

Thanks for any assistance.

Dean

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Well, there are actually six screws on the bottom, than the top of the case will lift off.  Just pull the fuse straight out and replace it with the fast blow 20A fuse.  If you're getting a transformer short on that channel, the top suspect is the TVS protection diode as mentioned, that one requires soldering on the board.  Here's the locations of the TVS diodes.

MTH TIU TVS Diode Locations

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  • MTH TIU TVS Diode Locations

If you need help repairing TIU just let me know ! be glad to help you! chances are if you blew a fuse and its still doesn't work might also might  need a TVS diode replaced in one or more channels ! usually if you have had a track short engine short or derailment the voltage spikes that are created will blow the TVS diode for a dead SHORT ! any time you have a spike even if your house powers voltage spike can damage your TVS diodes, I have even had a customer have a Tvs diode shorted because of the surge during the summer when his air conditioner compressor started  up caused a voltage dip causing a voltage SPIKE AND DAMAGED his  tiu THE SAME SPIKE can also blow an Engine Board!

Alan

Last edited by Alan Mancus
@Alan Mancus posted:

If you need help repairing TIU just let me know ! be glad to help you! chances are if you blew a fuse and its still doesn't work might also might  need a TVS diode replaced in one or more channels ! usually if you have had a track short engine short or derailment the voltage spikes that are created will blow the TVS diode for a dead SHORT ! any time you have a spike even if your house powers voltage spike can damage your TVS diodes, I have even had a customer have a Tvs diode shorted because of the surge during the summer when his air conditioner compressor started  up caused a voltage dip causing a voltage SPIKE AND DAMAGED his  tiu THE SAME SPIKE can also blow an Engine Board!

Alan

I have had numerous issues with derailments etc. so your scenario is more than logical.

Under normal circumstances I would probably just pick up a new TIU but with their availability in question and the prices they a commanding on eBay I am going to have to make due.

@John H posted:

I seem to have a blown TIU.

If you are not using all the channels, have you tried another? Do you have no power or a dead short? You haven't exactly described what the problem is. Is it just one channel? We could use some more info.

I have only used the fixed # 1 channel. I couldn't communicate with my MTH DCS Loc. Thought sure it was a blown engine board. Then took another MTH engine and put it on the track to confirm a bad engine and to my surprise it didn't work either. Since the other engine was brand new I knew I had to look elsewhere.

Fortunately I had another TIU put away so I tried it and bingo the original engine popped right up and went to work. 

Hope that gives a little more detail.

Thanks again to those who have responded.



Dean

@Alan Mancus posted:

If you need help repairing TIU just let me know ! be glad to help you! chances are if you blew a fuse and its still doesn't work might also might  need a TVS diode replaced in one or more channels ! usually if you have had a track short engine short or derailment the voltage spikes that are created will blow the TVS diode for a dead SHORT ! any time you have a spike even if your house powers voltage spike can damage your TVS diodes, I have even had a customer have a Tvs diode shorted because of the surge during the summer when his air conditioner compressor started  up caused a voltage dip causing a voltage SPIKE AND DAMAGED his  tiu THE SAME SPIKE can also blow an Engine Board!

Alan

Email sent.

S181715@aol.com

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