CW-80 Transformer Replacement Fan Radio Shack Part Number

[Anonymous]

One of my CW-80 fans stopped working, and I replaced it   The fan was an open circuit and did not work from a 12V DC bench supply.

Radio Shack part number 273-240 is an exact mechanical fit.  It uses the same voltage (12V DC) but has higher current draw (130 ma versus 70 ma) and  higher rated air flow.  It is also slightly noiser.  The circuit that powers the fan is insensitive to the higher current.

Opening the CW-80 is a real pain in the caboose.  Lionel (bless their hearts) used a very atypical security screw that has a recessed head shaped like an equilateral triangle.  I made a suitable tool from an old tool I had with a hand file in about 20 minutes.  After removing the screws, I replaced them with similar Phillips head screws.  The control handle just pulls off, so the nut on the control potentiometer can be removed.  Once you get the case off (the 4 atypical screws on the bottom), remove the screws from the heat sink that supports the fan and remove the fan (4 small ordinary screws).  The power semiconductors have to be detached from the heat sink to do this.  Then unsolder the two fan wires from the rather spatious (by today's standards) circuit board.  Pay attention to where the red and black wires go, they control the direction of the fan.

It is helpful to have some solder wick to remove the excess solder from the circuit board where the fan wires were removed so the holes are clear when the new fan wires are reinstalled.  It is also handy to have some thermal grease to lightly regrease the power semiconductors when they are remounted to the heat sink.  Pay close attention to how the internal wires inside the CW-80 are routed before removing the heat sink as the reassembly will be tricky unless they are routed correctly.  In particular, be sure they don't get between the case and the buttons mounted on the circuit board that control direction, whistle and bell.  If you power up the CW-80 to check the fan before putting the case back on, be sure the heat sink is positioned so it won't short to something else inside.

What possessed  Lionel to go to such extremes to make the CW-80 difficult to open is a mystery to me.  The 110V AC wires are completely insulated, and contact with wall voltage is virtually impossible.  Everything else inside is 18V or less. 

[mitchelr]

What possessed  Lionel to go to such extremes to make the CW-80 difficult to open is a mystery to me.  The 110V AC wires are completely insulated, and contact with wall voltage is virtually impossible.  Everything else inside is 18V or less. 

In a word......litigation.


Mitch