I have an MRC Tech II Railpower 1400 power pack from 20 years ago. A couple of months ago, I bought an MRC Tech 4 #260 to use in conjunction with it, with the help of Atlas (SPDT) Selectors. Before the final hookup of the new power pack to the selectors, I confirmed that the polarity was correct. Unfortunatly whe I switched on the power, the old unit suddenly started putting out full power, regardless of throttle position. It has been like this ever since, so I disconnected it from the control panel. It's just very basic wiring, I did nothing out of the ordinary, so is it possible that it just happened to die at this exact moment? It seems to be quite a coincidence, timimg-wise. I'm sure that lots of people do this succesfully, that's what the Selectors are made for. Is there anything I can do to repair this unit with some basic electronics knowledge? Thanks
Posted by Challenger (Member # 1298) on :
All MRC Power Pacs I have encountered have two sets of DC terminals. One set is "DC" and the other is "DC Track" The terminals labled "DC" put out a constant 12 volts DC current. The terminals labled "DC Track" is what is used to control the trains. In your situation, I would make sure that you didn't inadvertantly hook up to the "DC" Instead of "DC Track." For the record, Even though I am fully aware if this, It can still slip me up. Last week I had to pull my control pannel off because I am rewiring my layout to go to ground throws instead the side throw switch machines presenly in use. WHen I got to a good point to stop for the day and hooked up the power pack. I hooked it up to the "DC" and had the problem you described.