I don't post much, but log on almost daily and always seem to learn something from everyone here. I'm running HO using DC. Yesterday while running a pair of MU'd P2K switchers, they suddenly stopped.
After some trouble-shooting, I determined that "one"side" of my power pack had blown. I have Model Redtifier Corp's Tech 4 MRC 280 (dual DC controls). The "other side" of the power pack still works. I had an extra one (not hooked up yet) sitting around so it is now installed.
So, my questions are....is it worth getting someone to repair the broken pack? Or best to just buy another one? The one that broke has been getting moderate use since I installed it approx 1 and a half years ago. I have 4 of them in total......is it reasonable to expect that the other ones will fail soon?
I'm not much of an electrician and do not have voltage meters etc. I will also ask at both the LHS's here in town about repairs but any tips, suggestions and comments I get here will be greatly appreciated.
Many Thanks in advance
Max
Canadian Pacific
HO DC
I would not bother with it. Toss it and get a new one on there.
If that pack is burning up and shutting down due to heat during normal use, I would not want to use it anymore either.
I suspect that the packs themselves have nothing inside that is "User servicable" Probably that is a good thing because MRC is constantly advertising about how tough and robust thier power packs are with 24 engines or what-not.
As others have suggested, let it cool down for a good long time and then see if it doesn't come back to life. DC power packs all have "thermal protection". Something, either electronic or mechanical, senses when the pack is getting too hot and turns it off until it cools down again. It may take many many minutes for a hot power pack to cool down enough to to reset the thermal protection. Sometimes you have to unplug, or cycle power before the thermal overload resets. Thermal overloads for things like power saws are deliberately designed NOT to reset automatically lest the saw come back to life and start cutting just as the owner was fiddling with it. Some power pack designers may design the thermal reset as if it were a power saw.
Most power packs are good for about an amp at 12 volts. That's enough for a couple of modern can motor locomotives but not enough for four older Athearns consisted together. The best can motors may not take more than a quarter amp, the older stock Athearn motors can pull one amp worse case. I would expect a power pack to handle a pair of newish P2K switchers, unless then were very heavily loaded on a hot day, or you have some other electrical load like a dozen lighted passenger cars, or a shorting turnout or something.
If the pack needs more than just resetting the thermal overload circuit, no problem. A knowlegable electronics guy, or a electronically minded model railroader ought to be able to take it apart and fix it. Solid state electronics ought to last just about forever, so a repair makes the unit good as new.
David Starr www.newsnorthwoods.blogspot.com
CPMAXIM wrote:I don't post much, but log on almost daily and always seem to learn something from everyone here. I'm running HO using DC. Yesterday while running a pair of MU'd P2K switchers, they suddenly stopped. After some trouble-shooting, I determined that "one"side" of my power pack had blown. I have Model Redtifier Corp's Tech 4 MRC 280 (dual DC controls). The "other side" of the power pack still works. I had an extra one (not hooked up yet) sitting around so it is now installed. So, my questions are....is it worth getting someone to repair the broken pack? Or best to just buy another one? The one that broke has been getting moderate use since I installed it approx 1 and a half years ago. I have 4 of them in total......is it reasonable to expect that the other ones will fail soon? I'm not much of an electrician and do not have voltage meters etc. I will also ask at both the LHS's here in town about repairs but any tips, suggestions and comments I get here will be greatly appreciated. Many Thanks in advanceMaxCanadian PacificHO DC
when you say "blown" do you mean that the side stopped working completely? or did it just stop responding to throttle changes?
as i found out recently due to my own MRC meltdown, there isnt much going on inside the case of those things. basically it is a transformer, full wave rectifier, a pot, a resistor, cap and the voltage regulator - which is the "brain," so to speak, of the controller. its what in combination with your input on the throttle what the outgoing voltage is. its also where the overload protection is hiding.. it comes integrated in the IC as a feature and cant really be "fixed" if it doesnt reset itself. i would imagine that this is where your problem is. when i opened mine up i found that the model of regulator they were using was something that was widely unavailable.. so i basically had to rebuild my unit to accept a more "normal" regulator.
my railpower stopped working while under only a 0.6A load. so it seems that YMMV when it comes to those things. however, for a $20 trip to RS i was able to rebuild it into a dual control unit complete with a 50A full wave bridge rectifier and 2 1.5A voltage regulators. however i dont recommend you attempt to fix your unit unless you REALLY know what youre doing because there is LIVE and LETHAL line voltage involved.
Just wanted to let everyone know, it is back up and working! I got swamped with work yesterday, so early this morning, I read all your suggestions, plugged it back in and the power pack works fine.
My faith in MRC has been restored!!!!!
A big THANK YOU to all who responded........Max
Hi, I have a MRC 280 and one side stopped working. I took it apart and found 2 diodes broken. I replaced the diodes but still didn't give me any voltage to operste train. It reads 6.83 volts no matter where I turn the speed control. There is a device that looks like the voltage regulator but I can't find 2SD-1192 anyplace. I have to find more parts but MRC will not help me and asked to ship it back to them with $35.00 and they will repair it. If they would only ship me the parts I could repair it myself.
Does anyone have any ideas where to get the parts and there is no Radio Shack nearby?
A schematic would be nice too but MRC will not sghip that either.
Please help?
The 2SD1192 is a transistor made by Sanyo. Search '2SD1192 Transistor' and you'll get results from ebay as well as other electronic dealers. You can also find a cross-reference to a part with the same specs but made by other mfgs.
bibbster The 2SD1192 is a transistor made by Sanyo. Search '2SD1192 Transistor' and you'll get results from ebay as well as other electronic dealers. You can also find a cross-reference to a part with the same specs but made by other mfgs.
You got there first. I found this transistor on ebay. Some free shipping.
Rich
If you ever fall over in public, pick yourself up and say “sorry it’s been a while since I inhabited a body.” And just walk away.
richg1998 bibbster The 2SD1192 is a transistor made by Sanyo. Search '2SD1192 Transistor' and you'll get results from ebay as well as other electronic dealers. You can also find a cross-reference to a part with the same specs but made by other mfgs. You got there first. I found this transistor on ebay. Some free shipping. Rich
I have a Tech II Loco-Motion 2500 that needs repair and I don't know how to open it. There are six (6) retaining screws that look like allan heads except that the interiors are rounded so that conventional tools will not fit. What is the trick?
BART PULVERMAN richg1998 bibbster The 2SD1192 is a transistor made by Sanyo. Search '2SD1192 Transistor' and you'll get results from ebay as well as other electronic dealers. You can also find a cross-reference to a part with the same specs but made by other mfgs. You got there first. I found this transistor on ebay. Some free shipping. Rich richg1998 bibbster The 2SD1192 is a transistor made by Sanyo. Search '2SD1192 Transistor' and you'll get results from ebay as well as other electronic dealers. You can also find a cross-reference to a part with the same specs but made by other mfgs. You got there first. I found this transistor on ebay. Some free shipping. Rich I have a Tech II Loco-Motion 2500 that needs repair and I don't know how to open it. There are six (6) retaining screws that look like allan heads except that the interiors are rounded so that conventional tools will not fit. What is the trick?
On mine anyway, they are rivets and need to be drilled out to remove the head allowing you to pop it apart. I re-assembled mine with small self-tapping sheet metal screws.
Mark.
¡ uʍop ǝpısdn sı ǝɹnʇɐuƃıs ʎɯ 'dlǝɥ
BART PULVERMANI have a Tech II Loco-Motion 2500 that needs repair and I don't know how to open it. There are six (6) retaining screws that look like allan heads except that the interiors are rounded so that conventional tools will not fit. What is the trick?
The security screws use a T 10 anti tamper torx extended shank bit or a T 10 anti tamper torx screwdriver :
Jim
Quite a few years ago I had a MRC pack with those screws. They were to tough to drill out, ok, impossible. Found the bit at a local tool shop. No Internet back then.
Richhandle.
Harbor Freight has a security bit set for $7, however, if your screws are inset deeply, you may need the longer bit that Jim suggested
Henry
COB Potomac & Northern
Shenandoah Valley