FIXED smoke on GS4 6-11127 4/29 update

Well, that's the fan power supply, so it would certainly account for a lack of power!   However, the reason it blew could well be the associated diode, they don't normally go for no reason.  If the diode shorted, that cap would see AC, that will take them out just like that.

The diode is the larger component next to the edge of the board on the side with the cap.

No, but I've heard of it. So there's your problem (I guess) as that component must have been going bad; it's the other onboard one apart from the voltage regulator that I thought might be liable to fail. Someone other than me can tell you what you need to replace it but if possible I'd replace the whole PCB board.

Why it failed is the interesting riddle but I have not got a clue about that!

Actually, although replacing the whole board will obviously solve the problem, it would appear that about $1 worth of parts might do it as well.  I'd start with the diode and capacitor.

220uf 35V .315" Diameter SMT Cap, $.57/ea

1A Diode SMT, $.37/ea

Shipping from Digikey for small orders is only around $3 or so.

I ordered 5 of each. Won't hurt to have extra for other stuff. What else should I get from digikey while I'm ordering?  Molex plugs both male n female for testing/replacement on motor. Resistor for smoke unit? What size plug and resistor? TW

Well, you could go crazy, but I don't think you need anything else.  As far as testing the motor, you already have the connectors.  Remember, if you buy the connectors, you also need the pins and the crimp tool.   FWIW, those are JST EH family connectors, they're not Molex.

That's typically what I do. 5 of each??  I have other smoke units. 

Digikey has minimal shipping postage, so you can order again.

Works for me.  Trying to anticipate all the parts you might need to work on stuff hurts my head, mine have been accumulated over years. I normally end up buying stuff that I need and gradually accumulating inventory as time goes by.

This is some of the immediately accessible parts I have at the bench.

Each of those boxes looks something like this, this is my smoke parts box.

The larger items like PC boards, reverse units, trucks and power trucks are in stuff like this next to the bench.

It'll be a big order if you want all the parts you might need!

Of course, there's also boxes and drawers of other stuff to support my JWA product line.

Interesting storage cases. I'm curious what kind are they...

Lets see, I need some of those wicks, the smoke unit upper left looks familiar, an mth motor just in case oh, the resistors??? 

cjack posted:

Interesting storage cases. I'm curious what kind are they...

Harbor Freight specials.

TedW posted:

Lets see, I need some of those wicks, the smoke unit upper left looks familiar, an mth motor just in case oh, the resistors??? 

Let me just mail you that case, should fill all your needs.

Let me just mail you that case, should fill all your needs.

DEAL! 

Wait right there by the mailbox, let me know when it shows up.

Heh heh heh. Yup, n when it does my check is in mail. 

I was hoping you'd send the check first...

So Lionel has the pcb, part # 691-SSMUK02 as John suggested. Around $30. Fan motor part #6101154130 is unavailable. Resistor is 691RES8OHM.  Was 6 ohm but it got too hot, so Lionel suggests to go 8 ohm. Had to go to Brasseur Electric Trains for resistor and motor(out of stock). Also got some batting. I kinda think my motor is good so will wait for the rest of the parts and see what I need to do after install. TW

New PCB, resistor and batting. Smoking like a champ. TW

Lookin' good!

Nice job! Interesting that Lionel told you to use 8 Ohm instead of 6 but good advice if it means you won't have to do another repair.

It is interesting. Here's a copy of the email Lionel sent with the part numbers. Still don't have the motors, but as I suspected, mine was still good. So, all works great. Thx all for your help. Ted

The 6-ohm is also more likely to cook the voltage regulator board as it's a voltage control and Ohm's Law still applies in smoke units.   More current through the regulator triac means it's more likely to die a premature death.

I've got an 844 with what appears to be an identical smoke unit.  I just changed the batting and got it smoking great, but didn't change out the resistor to the 8. Do you think it would be prudent to do so?  Would reducing smoke output to medium or low have a reduction on current?  Thereby saving on wear and tear. TW

Well, in certain circles, there's a saying: "Let sleeping dogs lie".  If it's all working, I'd probably leave it alone until you have to work on it again.

I've taken a couple of these types of engines and opened up the smoke regulator package and bolted the triac to the frame for additional power handling capability.  If I'm all ready in there, it's a pretty easy upgrade.