Are TIU's repairable? Do any OGR members perform repairs? I have one that the number four(varible channel) is dead! It does nothing in fixed or varible mode. Thanks in advance for your help.
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@2ndhandrailroad posted:Are TIU's repairable? - Yes
Do any OGR members perform repairs? - Yes
I have one that the number four(varible channel) is dead! It does nothing in fixed or varible mode. Thanks in advance for your help. - could possibly be a fuse or the TVS diode. Not sure which REV. model of TIU you have, but if you can get the back off you may be able to replace the fuse if blown or the TVS diode, if you have good soldering skills. Check this thread:
TIU no power through fixed 2 after spark | O Gauge Railroading On Line Forum (ogaugerr.com)
Hi, look on the bottom of the tiu plastic case the rev will be their rev L are the best signal one's! what state you in!
Alan
If you're getting no voltage out of Variable #2, check the fuse first. If that's not it, the next suspect is the driver FET's, they can be replaced, but I'd probably let someone do it unless you're pretty competent at PCB soldering.
Well,I opened up my TIU last night(I have 3 and this was the first time Ive had to do so) and found an empty fuse holder!! I bought this one used and have no idea why it was removed. I didnt have any replacements on hand so I moved on to another project last night. So,I will buy a fuse today and test it tonight.
Bet I know why it was removed. Just like the one I was going through, the TVS diode on the output might have failed shorted and thus the channel is shorted. In the big picture of things, a relatively easy fix if you can solder. In fact, for testing, first just check for continuity across the diode in both directions. It should be open circuit at the voltage the meter tests with. If shorted- bingo. And you can cut one of the legs or both to remove from the circuit and test again.
https://ogrforum.com/...4#162475945162602124
and
Also, after replacing the fuse if you find the variable channel stuck on, there is a TVS diode next to the FETs that fails shorted when blown, and that is the place to test and swap that diode out for that type of failure (var channel stuck on and unable to turn off).
What MTH taught us is a quick cut one end of the tvs diode and check continuity that way you know exactly which diode is shorted and can be replaced! if the diode does not check shorted just resolder the cut leg and your back in business!
Alan
Well guys, thanks for the information! But that sounds like it could be above my skill set !LOL!! So if it turnes out to need more than a fuse,Which one of you can I send it to for repairs?
The forum member that repaired my tiu was GGG earlier this year .
In the past he also replaced a mth board in engine cab number 2195 N&W when the original 5v board went bad and did a professional job in doing so.
@Dieseler posted:The forum member that repaired my tiu was GGG earlier this year .
In the past he also replaced a mth board in engine cab number 2195 N&W when the original 5v board went bad and did a professional job in doing so.
Well, George is top shelf when it comes to repairs, so you made a good choice. 
Well,so far it works as it should after replaceing the fuse.
