I have a new-to-me ZW-C with (2) 180 bricks. I have no TMCC equipment. I have done the reset. I get the following vom readings with all levers set to OFF: A, .2 volts; B, 17 volts; C, .2 volts; D, .2 volts. With A at maximum I measure about 12 volts.
Is my circuit board fried? What are my options?
Replies sorted oldest to newest
I did as the manual described: hold in reset button while powering up the 180 w powerhouse.
Wire a light bulb across each output to test it.
Connect only one brick to the A Channel. Set all throttle handles to zero. Press and hold the reset button. Power on the brick. The red light will blink 5 times on and off. Then release the button.
Now the recalibration is complete. Power off the A channel brick and reconnect the second brick to the C channel. Jumper in B and D position.
Lionel product video. ZW-C. Start at 24:38 for the recalibration procedure.
You will get a small reference voltage when the handles are off. Essentially, .2 is zero to the trains. Nothing turns on.
Do it again with only one brick.
Well, I have recalibrated numerous times with same results. C and D channels seem fine, .2 v at Off and 16.9 at Max. However, A still has only 12.7 v at Max, and B has a constant 16.7 - 16.9 at Off, Max, or anywhere in between.
Dale, did you mean test with a light bulb to put a load on the circuits? Did you mean like a 12-18 volt accessory bulb, or did you mean a 120 volt bulb?
I use a normal train bulb - nominal 18V, so that I can observe changes in the output while probing with the 'scope. It also puts a resistive load across the output so that a high impedance meter will read properly if there is any slight leakage.
It sounds like you have an open FET in channel A and at least one shorted FET in channel B. You can use the "diode" resistance scale on a meter to compare the FETs for a good channel and the bad channels. There is a diode inside the FET that can produce strange results, but usually you can spot the culprits.
It's a good idea to insure any charge is bled off the FET before the measurement, helps minimize ambiguous readings.
well, perhaps you have an early production unit with the plastic support for the function lever assembly and the gears from the pots jumped a tooth or so.
Unplug the bricks, remove the four screws on top of the control unit and take a look inside.
Is the bracket metal? Move the A & B levers and observe the gears. Anything look strange?
here's some pics and a link to Lionel parts 6-32930
Access to this requires an OGR Forum Supporting Membership
