Old DC power pack not working?

Model Railroader Electronics and DCC
1

Hello,

I have a number of old DC power packs from Life-Like and MRC. The main one I have used to run trains on my small loop (while my big layout is being worked on) is a MRC Tech II Loco-Motion 2500. A day or so ago it worked fine with all my engines, but today I put an engine on and nothing happened. I triple-checked that the plug to my outlet was in right, which it was, and I also took the wires out of the terminals and put them back in again several times. Still, nothing has happened. The green light that shows power on the power pack lights up when I turn the speed dial, but the locomotive does not move. I have tried all my operable locomotives, and none work. They worked yesterday so can someone help me with this problem?

Thanks!

2

I assume the light is telling you the pack is live. Could you try a different power pack and see if it works? If yes, the pack needs work.

Do you have a multimeter (volt-ohm-meter)? You could check what the output of the pack is.

It’s possible you have a short on the layout tracks somewhere–screwdriver? NMRA gauge? but I think the overload light comes on in those cases.

3

first thing to do is check the powerpack itself, either a multimeter, or disconnect the track and hook up an automotive tail light bulb in its place … should tell you fairly quickly …

4

If the green power light is varying with the throttle, odds are pretty good the pack is working fine. Check the connections between the To Track terminals on the pack and your track.

–Randy

5

A cheap multimeter is a very useful tool in model railroading, but it’s probably safe to assume that it’s not putting out power. Old power packs die. There are no schematics available, the MRC probably needs a torx security bit to open the box.

The search function of the forum doesn’t work, but there have been a couple threads with pictures of the inside. Here is one such thread

Capacitors and transistors do not last forever.

6

A tail light bulb is a cheap way or the below is what I have used for some years.

http://www.trainelectronics.com/Meter_Workshop/index.htm

I put the expensive meter aside a long time ago.

At an autozone store you can find what looks like an ice pick with a light bulb in the clear handle and a wire with a clip lead. Cheap voltage tester I saw auto mechanics using many years ago whem I was a kid.

Rich