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Sounds like John's super chuffer is in order!
Unplug the smoke fan connector and measure the voltage at the connector. It should be 5VDC. If no voltage the small 3 legged 5VDC regulator is bad. That can be repaired easily. No need to buy a $50 smoke unit.
G
I can recommend George (GGG) He very kindly fixed my PS1 Challenger's smoke unit for a very reasonable cost - and I live in the UK !!
MIKE
These are pretty easy to fix, there are only limited things that can go wrong, and they're pretty cheap to fix.
It appears you tested the motor separately and it works. The following thread had the same symptoms and includes pictures of the likely suspect part (78L05) that GGG mentions and ordering info should you want to try a DIY repair. Otherwise, send it to GGG.
If it indeed turns out to be the 78L05 again, consider adding a heat-sink. You probably don't have vertical clearance to use the example heat sink shown in the other thread but I'd think you could fold or wrap a thin brass/aluminum strip or whatever without shorting anything. Epoxy it to the regulator case if need be. The bigger the better but even a small fin will improve radiator-like cooling and possibly save a future trip to the maintenance shed.
FWIW, I've added heatsinks to a number of Lionel smoke unit 78L05 parts, they are running pretty hot when they're pushing out 40ma or so for the fan. While I haven't added any to the PS/1 smoke units, I can see where that would probably be a good idea.
TO-92 heatsinks come in all shapes, so it's pretty easy to find one that will work for most applications. I have also used thermal epoxy to simply glue a strip of aluminum to these and other chips to provide heat dissipation.
Probably not, as you don't have a chuff switch, and the audio is internally generated from the track voltage and has no real bearing on how fast the locomotive is running. You have to have some sort of discrete chuff input for my board to function properly.
I rarely have to replace a 5V regulator on a PS-1 smoke unit. Maybe that bad batch of Lionel smoke motors cause issues with Lionel's regulator, which is only receiving half sine wave input. MTH gets a fully rectified DC input.
I would think a bad motor or a short would be the cause of a regulator going rather then heat.
While some motors will run on a battery fine, that doesn't mean they are good. They could draw excess current which a battery can easily supply while the regulator can't. I see the same in PS-2 smoke units. G
I never test motors with a battery, I use a bench supply with meters so I can see what current is being drawn. I agree with GGG, I don't recall ever replacing the 5V regulator on the PS/1 smoke unit. I know that the last two Lionel ones that had bad regulators had the diode fail, that took out the capacitor and the regulator as well. But I've also found them just with the regulator bad. A couple Lionel models actually come with a heatsink on the regulator, so apparently Lionel must have recognized it's running near the edge.
I don't know where you live in Michigan (per your profile) but there are 17 Harbor Freight stores in your state. Here's their FREE meter measuring the 5V 78L05 output of a PS1 smoke board. I am over-run with these coupons for an absolutely FREE meter (no purchase required) in the Sunday paper, in magazines, etc. Even a basic meter can go a long way in troubleshooting these electronic widgets.
You are welcome! G
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