MTH DCS TIU Repair Parts

did u take apart the tiu and check the fuses first? what makes you think its a fet there are other parts inside the tiu that control the tiu output.

here is the fet mth part number for tiu!

BB-0000053

fet

Alan

The part is the IRFZ44N, and they're pretty cheap.  They are a bit "long in the tooth", so not all distributers carry them.

If you're in a hurry, Digikey has them for $1.13: IRFZ44N at Digikey.

If you're a bit more patient, Aliexpress has them dirt cheap, less than $2.00 for ten shipped: IRFZ44N at Aliexpress.

Thanks for the helpful info.  Had nothing but problems with everything MTH I have bought.  This unit has been in for repair to Columbia once before for an FET replacement.  Don't want to have to deal with them again.  Hopefully I can resolve the problem.

here is a picture of the tiu board there are 4 fets per each channel variable . look at the 4 in the middle with metal shields you would have to take the screw out of the one your replacing and after you unsolder it put the new one in. make sure u use heat sink compound it is used to transfer the heat of the fet away so it don't overheat!

If I'm replacing all of them, I just remove all the heatsinks, then clip off each FET right at the body leaving some of the leg in the board.  Turn the board over, connect forceps to a leg hanging below the board, heat the connection and the leg will fall out.  Repeat for all of them.  A little cleaning of the holes, and you can solder in all the FET's.  I put the heatsinks on first and then install them.

otww posted:

Thanks for the helpful info.  Had nothing but problems with everything MTH I have bought.  This unit has been in for repair to Columbia once before for an FET replacement.  Don't want to have to deal with them again.  Hopefully I can resolve the problem.

Ah, Yes.....MTH has the best looking and best operating system in the train industry,WHEN it all is working!!!Unfortunatly,the quality control  is non-exsistent,as it is with so many manufacturers today.

You are correct with your judgement not to send anything to Columbia,besides the extremely long turnaround time on repairs,I actually know a guy who sent 3 Premier diesel trains in for repair, and they actually LOST the 3 trains!!!! After over a year,MTH did REPLACE his 3 powered diesels, but the stories he was told while they were trying to locate his trains, were beyond unbelievable.  

I myself LOVE MTH trains, and have found you are much better off asking for help from the MTH Certified Techs or other great people here on the forum, if and WHEN you run into repair problems.These guys have a wealth of knowledge,and will answer your questions and even offer to fix your stuff for a fee.  

I wish the situation with MTH repairs would be different, but it has been THE ONLY problem that folks have with them, and I looks as though it will continue to be more of the same.  

Stick with the techs on here, they are your best bet when you need something fixed, and would like to have it back in a reasonable amount of time.

John,

I have an 2 MTH TIUs that I’m running 4 channels  powered by 4 separate on one, and one (fixed out ) channel on the other.  I’ve run this for a couple years.
the other day I was running trains for 10 minutes when Variable 2 on TIU tripped the breaker on its transformer. After eliminating possible track shorts, I disconnected the power out on Variable 2. Same result Variable 2 trips transformer breaker (tried 3 transformers).
After reading this discussion and I’m wondering if you may be able to help me with the repair.

Hennings Trains also referred me to you.

Thanks,

Mike

I can help if John is busy.  G

On this note, does anyone know what the replacement part number is for the banana jack posts? The 4 in/out posts across the top row.

Dual female binding post #    BB5100004

I'm sure you can find these elsewhere as these are used on speaker amplifiers

@Allan Loczy posted:

On this note, does anyone know what the replacement part number is for the banana jack posts? The 4 in/out posts across the top row.

I ran too many engines on fixed 1 one time and the post actually began to melt!  Like joe Allen mentioned, you can find them on Amazon for cheap and it’s a simple repair/change out. I think this is the brand I went with - https://www.amazon.com/Alotm-T...mp;returnFromLogin=1

@Strap Hanger posted:

I ran too many engines on fixed 1 one time and the post actually began to melt!  Like joe Allen mentioned, you can find them on Amazon for cheap and it’s a simple repair/change out. I think this is the brand I went with - https://www.amazon.com/Alotm-T...mp;returnFromLogin=1

Actually, they most likely started to melt because the nuts on the inside were loose and allowed a high resistance connection to heat up and start melting things.

@Strap Hanger posted:

I ran too many engines on fixed 1 one time and the post actually began to melt!  Like joe Allen mentioned, you can find them on Amazon for cheap and it’s a simple repair/change out. I think this is the brand I went with - https://www.amazon.com/Alotm-T...mp;returnFromLogin=1

Actually the problem is that the nuts were too loose causing the connection to overheat. They should be able to handle more amps than your transformer is probably putting out. This is a known problem and I have always found at least one connection not tight enough. The MTH posts only have one nut. I  added another nut to them. I placed the wire terminal betwen the two nuts and lock washer.  No more problem. The MTH transformers have the same posts and they have the wire terminal between the nuts. Go figure.

@Joe Allen posted:

Actually the problem is that the nuts were too loose causing the connection to overheat. They should be able to handle more amps than your transformer is probably putting out. This is a known problem and I have always found at least one connection not tight enough. The MTH posts only have one nut. I  added another nut to them. I placed the wire terminal betwen the two nuts and lock washer.  No more problem. The MTH transformers have the same posts and they have the wire terminal between the nuts. Go figure.

Too funny! When i did the repair and replaced the melted banana plug terminal, i noticed that the original nut was loose.  I thoroughly tightened the nut on the unmelted  replacement and all has been well ever since.

Kenny it's not that mth is taking to long to repair items!! they now only repair warranty work everything else is sent to asc techs only!

Alan