Engine sound on Lionchief Polar Express

On Lionchief steam engines the speaker is in the tender, the control board with sounds is in the engine. The tender is connected to the engine through the drawbar which also has electrical contacts.

The typical failure is either the the contacts in the drawbar connector get bent or damaged and intermittently make contact (given when the engine pushes he tender backwards, this pushes the contacts together and your sound works) and he fact when the engine pulls the tender, the only thing holding the contacts together is the plastic drawbar, if it was cracked, it could flex and thus break contact causing speaker dropouts.

Another known failure is the very thin wires that are soldered to the drawbar system have heatshrink over top that is supposed to provide strain relief from flexing and then breaking at the solder joint. This is usually another failure point and I probably repair 10-20 of these every year at the local shop. The bad news is when this breaks, if the wires touch the outer rail connection also present in this 4 pin connections, because that is AC, it blows minimally the sound amp chip on the Lionchief board or worse case destroys the entire board with AC current up DC circuits.

We need to know the exact product number of your set to ensure getting the right part since Lionel has made different versions of the Lionchief boards and some do have different connectors (before blueooth, with bluetooth, Bluetooth 5.0).

As an example a 5.0 set engine side https://www.lionelsupport.com/...RESS-5.0-ENGINE-ONLY

tender side of the connection (15th anniversary tender)

https://www.lionelsupport.com/...NDER-ONLY-1923031T01

Is the intermittent sound such that it A) cuts in and out while continuously going forward, B) does the sound sometimes work and stay on while forward is selected until stopped or the direction is changed or C) both?

Also, these use an optical flag sensor to trigger the chuff sound that depends on the lever pushing the piston driven by the cam goes full stroke up and down. It's possible for the plastic pistons to stick up and then that can affect the lever not cycling. But again, this only affects the chuff sound making it intermittent, other sounds such as whistle, bell, and announcements all work normally.

I've seen over time on a "high mileage" engine, the chuff cam plastic piece wear in length and slowly over time begin to lose the length of the stroke. Part number 45

But again, the more common thing was sticky smoke fluid, coupled with plastic maybe swelling, and just interference, the fit of the piston begins to get stuck up in the bore (tapered because of injection molding) and the return spring not strong enough. Oddly, Ive seen this also be directional in nature- just another oddity of the design. Again the return spring (number 67) is a very light spring intentionally and if the piston sticks or jams- typically up position, then it won't push back down on the lever for another stroke.

Again, 5.0 engine example https://www.lionelsupport.com/...RESS-5.0-ENGINE-ONLY

@SteveH posted:

Is the intermittent sound such that it A) cuts in and out while continuously going forward, B) does the sound sometimes work and stay on while forward is selected until stopped or the direction is changed or C) both?

It cuts in and out while continuously going forward.

Thanks

Jeff

Is it just the engine sounds or is it all sounds (engine, whistle, bell, and announcements) while going forward?

Just the engine sound,

@Jeffery Boat posted:

Just the engine sound,

Background sounds or just the chuff?

Just the chuff.

Top suspect is the chuff switch.  It's an optical chopper that frequently doesn't make the full stroke as Vernon describes and you end up missing the chuffs.