Another legacy smoke issue

The reg you changed has to be from a Legacy locomotive.  It sounds like you did the right thing.  Paul, remember one wire to the reg is data.  Do a continuity check between that wire and pin 24 on the R4LC board.  The R4 might not be talking to your reg.  If you have another R4LC swap it out and see if that gets you up and smoking.

 

If no luck, check for 6 ohms across the smoke heater.  You could have cooked it.  Did you do a reprogram of the R4LC to restore features?  Heavy smoke and burning can be seen when the smoke fan motor dies.  I replace many of them in a month in SD-70 locomotives.  I actually have your locomotive and did a smoke motor before York.  The fact that you have no voltage, look at what I first mentioned.

Thanks Marty. I wish I had  flowcharts for these things! I'll post my results of your suggestion.

This"triac" is on the r4lc board itself?  Thanks.

Yep, it's on the edge of the board near the connector in this picture.  Right below C14.

 

Is this triac round and blue in color?

Ah!!  I had heat SHRINK  and not heat SINK on my mind so there's the reason I missed it. You just replace it or do you do a test first? I thank you for your help.

First verify that the wiring and smoke unit are good, then if when you command smoke you get no voltage out of the R4LC, that's the top suspect.

 

If you don't have the proper tools to work on a PCB, I'd get someone to change it, it's easy to wreck the PCB.  I normally break off the old one so I can unsolder the pins one at a time, then clean the holes and install the new one.

Amos, On your Legacy diesel with an AC regulator, the AC regulator controls the power to the smoke unit and the amount of voltage that is supplied to the smoke heating element.  The AC regulator gets it's power from track power (18VAC) and is turned on/off using serial data from the R4LC unless you manually turn it off by the on/off switch that interrupts power from the track. 

The R4LC Legacy receiver does not provide power to the smoke unit as it only communicates with the AC regulator through serial data.   It tells the reg to turn on/off.  This is different form TMCC. 

The fan motor is powered from the same AC regulator and the fan power gets regulated to 5VDC from a 5V reg on the PCB for the smoke unit. 

Please plug in your spare R4LC board to see if you can communicate with your regulator.  If no luck, please get back to us.

 

Thanks Marty, I thought that triac was still the smoke unit.  Since it's still the large one, and the R4LC is used for ERR's kits and it does control the smoke directly, what is that traic used for in Legacy locomotives?  Is that an unused output?

John you are correct on that.  One that comes to my mind was the Lionel Pennsylvania Mikado JR.  That sometimes came with an R4LC and was not a fan driven smoke unit.

That's the great thing about this forum, learn something every day!   I haven't had any issues with the smoke units of my Legacy units yet, other than repacking them a couple of times, so I didn't look that close.

 

Thanks for jumping in with a correction, don't want to send folks down the wrong trail.

John, I read everything you post and have learned a lot from you.  The problem Amos has is just something I run into often and not because I am a wealth of information.  I do the Legacy/TMCC repairs for Charles Ro and get to see this situation often.  Many situations in Legacy are not the same with TMCC.  One common point is the R2LC board in TMCC giving 5VDC to the DCDR.  In Legacy the R4LC does not do this and the driver board gets it's 5VDC from a 5V regulator on the motherboard.  I have 4 Legacy diesels and have been into 3 of them with like problems.

Well, when I have to dig into my Legacy stuff, I'll at least know where to look!

 

Both of my steamers are still under warranty, as well as my U28C, but the older diesels are now in my ballpark if they have issues.

 

At least I correctly identified the triac, even if it's not used for this locomotive.

John, I am always happy to share any info I can for fellow Forum members.  One thing about working for a large dealer is I get to see many situations as Charlie does sell a few engines.  It also helps to have all the tech books and contact with Canfield.

I'll remember you have all the books.

 

I'd love to find some information about the Legacy locomotives, like wiring diagrams!

I will try my spare board and post results. I was surprised by the "triac" idea as I had no idea what it was nor had I heard of it before but I was willing to learn!! I only knew of the ac reg. controlling the smoke unit.

 I concur on the wish for wiring diagrams.

Well, I just found out that I have no spare r4lc board. I am willing to order one if that's what I need to do. I understand it's not a guaranteed fix. Does that 110.00 board play a role in smoke? Again, thanks for all of the help.

I do not know where you got that price.  They do not cost what you stated.  Did you check continuity from the rollers to the smoke reg and ground to the smoke reg?  Next the continuity from the hot side of the reg to the smoke unit hot and the ground on the reg to the ground on the smoke unit?  If you have continuity on those positions, check serial on the reg to pin 24 on the R4LC.  I asked earlier if you used a reg made for Legacy.

I would think the R4LC board would be more in the $40 range like the R2LC, they're pretty much the same.

Hi guys:
I am a total Legacy newbie, but on the subject of smoke- I've got two Legacy geeps- they smoke like chimneys in conventional, but when I (finally!) hooked them up to my command control situation- nada. The toggle switch is set to smoke. What's teh default setting for smoke in legacy? How do I turn it on? Sorry for such basic (and in you're guys minds, probably stupid, questions), but I read and reread the manual and couldn't figure it out. Thanks for any insights you might have!

 

Try this.  Good video on Lionel Smoke units!

 

 

Thanks, Marty- I will!

I'm back-the 110..00 figure was not for the r4lc board. It is for another board in there. It's the one behind the front engine(motor). I just wondered if it factored in. I ordered a r4lc board yesterday from Lionel (54.00). It should be in in the beginning of the week and I'll try it out. Again guys, thanks.

  REGARDING THE 110. 00 BOARD, I simply seemed to smell that burnt smell from that area. The wires that burnt were behind the smoke unit. I kind of figured with my luck it would be the most expensive board in there!

 The regulator I put in is from a legacy unit. I do wish there was a schematic of this system.!

Amos, Did you ever get this fixed?  I am working a N&W J (2006) with TMCC not legacy, and it has super smoke so the set up similiar.  There is serial data going to the ACREG and also to the smoke unit directly.  So even with some TMCC engines, it looks like the R2LC Smoke triac is not used.

 

I am trying to trouble shoot whether I have a bad smoke unit, or a bad ACREG.  G

I'd be tempted to try to repair the regulator board it that's what it turns out to be.

Amos, Thank you for the response!  I got the N&W fixed also, turns out the heating element lead was too close to the case of the smoke unit, as it heated up it was grounding the ACREG power causing the short.  Luckily the ACREG didn't blow.

 

The REGs I have seen, those 2 black ground wires are common ground.  My unit was different in that the ACREG and the Smoke Unit both had separate AC Power and Serial data going into them.  The ACREG has one Hot AC out going to the smoke unit heating element only.  The Smoke unit rectifies and controls the smoke unit fan.  It uses the Serial data line to turn it off and on, and the chuff signal on the serial data line controls the syncronized puffing of the smoke fan.  That is why in neutral the smoke fan is off and the smoke output stops even though the heating element is still on.  Mine was a Code 4 ACREG.   G

I have a smoke unit that works flawlessly with the same wire snipped so not sure what that's about.

 

Well, I opened the pack and voila! The ground wire for the a/c reg unit had been snipped off at the reg board leaving a stub .

Depends which engine you have, some may need the wire, others don't.  Lots of smoke unit variants.  G

Marty, it is funny because I wired it up without it first just to see if it somehow would work without it but no go. I then of course added the ground and all is good. This ground was specifically for the ac reg. to operate (send) the power source to the smoke unit.

 GGG-My loco is a diesel;hence,smoke continues even when loco is just at idle.

 

 Now this may sound strange but this is a part of this hobby that I enjoy. I work on cars for a living and  I work mostly on computer diagnostics. I enjoy pouring over wiring diagrams and schematics to detect problems. I get a sense of satisfaction and I get to see the results of my work on a regular basis. I have no such information for these trains- I have to trace each wire by hand; however, I get to learn quite a bit about the loco this way.

 I have found in my experience working on theses locos that two of the same type of locos can have internal differences. Also, a loco can operate differently than what the manual that came with it says. Example: I have a Chessie ac6000 on which the ditch lights work via the aux2 button. The manual specifically says you operate them with the "on" and "off" icon keys on the cab2. Lionel told me to send it in and I did. They sent it back and said it was operating as intended. I called and they said sometimes the manual is just wrong. Puzzled by this I called again and spoke to a different person and got the same answer. I have no idea why they asked me to send it in to begin with! The manual has a section specifically for these lights and their operation on a page by itself. It's clear and never mentions the aux2 button in conjunction with the ditch lights.  Oh well!

I thoroughly enjoy working on them. 

While we are not fans of walking folks thru repairs (mostly because more problems arise than necessary and we can repair it more quickly and correctly in house, albeit sometimes for a fee, but we'll save that conversation for a face to face chat in the future!). The Legacy regs have 5 wires: S = serial, r4lc pin 24 H+ = smoke unit hot H- = ac ground / chassis ground (smoke unit ground) + = ac hot / collector - = ac ground / chassis ground You can see there are 2 grounds, hence some locos have 5 wires coming out of the reg and others have only 4. It is IMPERATIVE that the triac be electrically isolated from the chassis where it is mounted! If it is not isolated it will self destruct as soon as power is applied! In the case of the sd70 in question all you needed to do was change the reg (691acrg103) and the element (691res8ohm) and the problem would have solved. Again, a 2-day turnaround in Ohio, tested for 3 hours and promptly returned without wasting money on components you didn't need! I understand wanting to work on your trains, but I cringe every time I see guys spending money on components they do not need! I know some service facilities will throw in parts that are not necessary to bump up the cost! That is NEVER done in Lionel Service! We fix the "problem" run your item for 3 hours to confirm we have not overlooked any potential heat related issues, QA the repair and promptly return it. Everyone is service is accountable for their work and we all take pride in providing the best service to the best customers! Sorry for the rant, Mike

no need to be sorry Mike, we like hearing from you.  it is not every day someone from the "top" speaks directly with the customer.