# My 6200 MRC bit the dust it seems



## Randy Stone (Jan 2, 2008)

Well, I was pulling my California Zepher Express with the two FAs and had my two NW2s out ahead when all of a sudden they sped up. I turned the speed control down but they didn't slow down. So I turned the handle down to zero to stop the trains and they just kep going. Finally I hit the on off switch and the trains came to a stop. The transformer has *popped* the over load before but the trains always came to a stop and after sitting for a few minutes they ran again. If the transformer was to fail, I expected the trains to stop running, not speed up. I haven't tore the transformer apart, but I'm guessing it isn't a wire burnt in to on the reastat. Guess it's time to buy one of those MRC 10amp transformers.


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## Jerry Barnes (Jan 2, 2008)

Mine did the same thing, could still use it with the TE, since it was putting out top speed all the time. Got an Aristo 10 amp.


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## toddalin (Jan 4, 2008)

Nope. One or both of your MOSFETS have shorted out internally allowing full voltage off the "rail." I've had this happen to me and replaced one of the two. I'm looking at one and it is labeled D1229 4C. There is a "special tool" to open the MRC case, but I use side cutters.


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## dbodnar (Jan 2, 2008)

Posted By rlvette on 30 Mar 2011 06:34 PM 
Well, I was pulling my California Zepher Express with the two FAs and had my two NW2s out ahead when all of a sudden they sped up. I turned the speed control down but they didn't slow down. So I turned the handle down to zero to stop the trains and they just kep going. Finally I hit the on off switch and the trains came to a stop. The transformer has *popped* the over load before but the trains always came to a stop and after sitting for a few minutes they ran again. If the transformer was to fail, I expected the trains to stop running, not speed up. I haven't tore the transformer apart, but I'm guessing it isn't a wire burnt in to on the reastat. Guess it's time to buy one of those MRC 10amp transformers.


*The MRC6200 is very easy to repair - I had to deal with 5 of them at a layout that the Pittsburgh Garden Railway Society maintained a few years ago - I wrote up the most commonly needed fix - have a look here:*

MRC 6200 Repair 

Let me know if you have any questions.

dave


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## Don Howard (Jan 2, 2008)

Dave, 
Thanks for the link and creating an easy to read article. I've saved it in case mine misbehaves! 
Now to find a fan!


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## Naptowneng (Jun 14, 2010)

Much tnaks for the article. Great reference. Do you happen to have the specs for the pilot light and the replacement protocol? My 6200 ususally stays at full throttle as it feeds my TE transmitter, and the pilot light failed. Nice to have as a visual reference. 

Go for it Randy!

Thanks

Jerry


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## dbodnar (Jan 2, 2008)

Posted By Naptowneng on 31 Mar 2011 06:13 AM 
Much tnaks for the article. Great reference. Do you happen to have the specs for the pilot light and the replacement protocol? My 6200 ususally stays at full throttle as it feeds my TE transmitter, and the pilot light failed. Nice to have as a visual reference. 

Go for it Randy!

Thanks

Jerry

Jerry - I do not have specs for that bulb but would think that it needs to be rated at 20 or more volts as it believe it is connected directly to the output of the power supply.

You could substitute an LED if you used a 1000 or 2000 ohm current limiting resistor. You would also need to check to see if the bulb is always fed DC of the same polarity if you go with an LED. 


dave


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## Randy Stone (Jan 2, 2008)

ok 

Side cuts to open it up? 

Maybe a pair of channel locks? 

Are these threaded or what? 

Thanks Dave 

You tech article is great. 

Guess I'll head out to the garage and see if I can open it up. 

By the way, this 6200 has the silver case. 

Randy


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## dbodnar (Jan 2, 2008)

Posted By rlvette on 31 Mar 2011 05:32 PM 
ok 

Side cuts to open it up? 

Maybe a pair of channel locks? 

Are these threaded or what? 

Thanks Dave 

You tech article is great. 

Guess I'll head out to the garage and see if I can open it up. 

By the way, this 6200 has the silver case. 

Randy 
Randy - if you can't get the security screws out with side cutters or vise grips try grinding a slot in them with a Dremel - they are threaded - normal thread.

Good luck!

dave


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## toddalin (Jan 4, 2008)

Just grab the heads any way you can and twist them counterclockwise. There is a regular screw thread attached to the security head that threads into the case. Both of mine are also silver cases.


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## Del Tapparo (Jan 4, 2008)

Nice write up Dave. Boy, if I was MRC, I would be really embarrassed about the "workmanship" in that silver case. That is about the saddest mess I have seen in a long time, and never from a product being sold to the public. A beginner's first project? Maybe. Wow! That is really nasty.


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## Randy Stone (Jan 2, 2008)

Thanks Dave and Todd 

Del, the wiring reminds me of the stories about Aristo Craft's wiring. 

I believe it's what we used to call a rat's nest.


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