RCMC board failure?

I think you would have seen a bad motor issue.  Check the usual with respect to pinched or damaged wire, smoke unit, etc...

I would also inspect the board and see if you can locate a damaged area.  If so, ask lionel and they may tell you want that component does which leads you to a possible source.

At the same time, the board could have just died with no cause other than a component failure.  G

I've had two Legacy engines with the Canon motors that shorted and both took out the RCMC board.  There was visible damage, the FET's for motor drive were toasted.  I was under the impression that the RCMC should sense this, but in these cases, that didn't work.  A new motor and new board and they were back on the road.

I'd check the motor with a DC supply, and pay particular attention to the current draw.  The one bad motor I had would actually run, but it took about 4 amps to spin it at any speed on the rollers!  The new motor after installation would run on the rollers on less than 1/2 an amp.  The second bad motor was a direct short, it did nothing but conduct electricity.

Thanks for the replies and advise.  I'll take a closer look at the motor as the culprit, as well as a closer look at the board and report back.  Will likely be tomorrow as the NFL occupies the main line on Sunday. 

Bruce

Upon further testing the motor appears to be fine.  It spun up nicely with a 9V battery.  I let it run for 3 minutes just to ensure it wasn't drawing excessive amps.  Lionel was supposed to ship the new board today and they said 7-10 days, however since they're only 2 states north of Georgia I'll hopefully have it sometime mid-week.  I'll check back in once the board is received and installed.

Bruce 

In that case, before the motor installation, I think I'd make sure there are no pinched wires that have caused the failure. 

you mean board installation right?

Motor, board, what's the difference?

Yes, I mean board, I'm still pushing bad motors it would appear.

Well as you know that is a bit of an easter egg hunt on these engines.  With the motor and the board removed there is fairly clean access to wiring close to and against the frame.  I didn't notice anything unusual and there is no wiring near the wheels.  The smoke units were turned off at the chassis switch so they should not have caused the board to fail.  The main power harness coming from the track pickups is not shorted, which leaves the pin out harness's to the various engine lights and firebox. There is also the motor sensor board which I guess could have failed and taken out the main board, but there's just no way of knowing.  Once the new board is received my plan is to connect the main harness and then start powering up the various connectors one by one until everything is back in place.  Assuming the short is cleared I'll put the motor sensor board on last and keep my fingers crossed.  Now that I think about it I should have spent another $18 and purchased that board also.  Hindsight is 20/20.

Let me know if I'm missing something obvious. Thanks!

Bruce

After 3 weeks finally received the new RCMC board.  The board solved the dead short problem and the engine operates as a Legacy engine should except their is no chuff. Have all other RS functions ie: whistle, bell, crew sounds, etc.  The lights all function and respond to commands.  The smoke unit works, however it does not puff, just blows a steady stream of smoke when the engine is underway.  I have double checked all of the connections, done a hard reset, checked volume levels and reloaded the engine into the Cab 2.  Is there a reed switch I should be looking at?  There is not one shown on the parts breakdown for the engine or tender.  This is a wireless tether set-up.  Any suggestions would be welcome!

Thanks,

Bruce

Try a reset, which is just reprogramming the TMCC ID.  I'm pretty sure the chuff rate is generated internally, and the smoke unit is controlled from the RCMC directly.  The smoke unit is dumb, no logic.  There's really nothing else you can "fix" that I can think of.  If that doesn't do it, I'd call Lionel and ask what gives.

Thanks for the input.  I tried a few resets without success.  I gave Lionel a call and Customer Service advised this is their busy season and they did not have a technician available to discuss the problem. They asked that I send an email outlining the problem and they would try to respond within 30 days. Fair enough I guess, so the K-4 is in limbo until further notice. I actually ran it the other evening with a railsounds boxcar and it sounded pretty good.  I'm only missing the chuff and the boxcar is a credible substitute. I'll post the final outcome once there is one.

I wonder if I'm just missing the chuff switch, just having the chuff missing sure sounds like a mechanical switch.  I looked at the parts breakdown again, no switch.

I have to believe this was simply programmed incorrectly at the factory.

When I spoke with the Customer service rep one of the first things she mentioned was the cherry switch.  I said OK, where's it at on the parts breakdown.  After a minute or so she put me on hold and when she returned she advised the engine had no cherry switch. 

I looked over the new board and it's the same part# and revision (5) as the one I removed.  There is no way to determine the firmware as this is privileged Lionel Info. I spelled everything out in the email I sent to them and I'm guessing that eventually they will exchange the board for one that works or as you said is programmed properly. Since they're currently busy selling Polar Express sets it may be a few weeks before this issue is sorted out.  Thanks for your thoughts and suggestions.

Bruce

Yep, I'm sure they'll eventually make it right.  Most of the Legacy locomotives with four chuffs/rev don't use the cherry switch.