Lionel DCDS-F

First off, before you do anything with the DCDS, I suggest unplugging the 6-pin connector that powers the motor from the DCDS, connect a DC supply with 6V out to the motor and see how much current the motor draws.  If a replacement DCDS is struggling, it's likely because of something besides bad driver boards.

That was one of the first things I did motor pulled well under an amp on the bench power supply. I can do it again to get an exact mA reading but it was definitely in that range on rollers.

I definitely agree there has to be something causing bad motor drivers.

I did notice the marker lamps would pull .17A at 3VDC (pretty sure that’s what I was getting)

Zach, I’ve had a few TMCC steamers with the same complaint,….I’ve never been inside the ATSF Northern, but it all the cases I’ve seen, something was touching a motor solder lug causing the odd behavior. In all my cases, it was how Lionel mounted the motor, with the solder lugs facing down, inadvertently close to the frame. One bad bounce, and they touched. If the lights are flickering, there’s a good possibility something other than a bad driver is pulling them down, and making the motor go stupid…

Pat

Thanks for the idea Pat. Again I know there has to be something else here but I can’t seem to find it.

from what I can tell I don’t see how the motor leads on this model can hit anything. attached is it running at 6VDC hooked to the drivetrain on rollers.

this has a 9433L187 Pittman anything else I should check on the motor?

Personally, I'd recommend shrink-wrapping those motor leads. I could see that trailing truck pivot hitting on entrance to an incline.

The driver could be going flaky, but naturally as John said, rule out the variables. By your meter’s numbers, it looks like a healthy Pittman. Does the issue arise running in command with the shell off and the class lights and whatever else is on that circuit disconnected from the driver? ……..pretty much any large steam Oddesy driver could run that engine, it’s how they’re programmed for the accessory outputs, and some differences in Hall effect vs. gear ratio differences, but they’ll run one another for at least testing purposes,……I used to have oodles of these, but with the vanishing act of TMCC parts, a lot of techs have dwindled me down to a few heat sinks left in the bottom of the barrel,…..😁

Pat

@zhubl posted:

That was one of the first things I did motor pulled well under an amp on the bench power supply. I can do it again to get an exact mA reading but it was definitely in that range on rollers.

The motor should be drawing way under an amp on the rollers.  A good place to test my gee-wiz DC clamp-on meter.  Looks like around 1/4 A for this Y6b on the rollers.

@rplst8 posted:

Personally, I'd recommend shrink-wrapping those motor leads. I could see that trailing truck pivot hitting on entrance to an incline.

That was my immediate thought when Pat mention the motor terminals but I tried pushing up on that pin it’s locked in place.

@harmonyards posted:

The driver could be going flaky, but naturally as John said, rule out the variables. By your meter’s numbers, it looks like a healthy Pittman. Does the issue arise running in command with the shell off and the class lights and whatever else is on that circuit disconnected from the driver? ……..pretty much any large steam Oddesy driver could run that engine, it’s how they’re programmed for the accessory outputs, and some differences in Hall effect vs. gear ratio differences, but they’ll run one another for at least testing purposes,……I used to have oodles of these, but with the vanishing act of TMCC parts, a lot of techs have dwindled me down to a few heat sinks left in the bottom of the barrel,…..😁

Pat

Well so this had sat for a year or two because like I said a different repair tech replaced the driver before that questionable day at Lionel 😅. so far I have yet to recently get it to act up minus the continuous flickering markers I’ve put a scope on the marker output unloaded and could see it jumping around of course I don’t know if unloaded really tells me much. I might just leave it on rollers for 30 min one night in conventional and command and see if I get anywhere.

@gunrunnerjohn posted:

The motor should be drawing way under an amp on the rollers.  A good place to test my gee-wiz DC clamp-on meter.  Looks like around 1/4 A for this Y6b on the rollers.

Yeah I went back and checked again on rollers at 6VDC it pulled .29A

@zhubl posted:

Yeah I went back and checked again on rollers at 6VDC it pulled .29A

That seems pretty right.  Make sure neither motor lead has any connection to the frame, then it's time to consider the DCDS.

The flickering markers may be a clue, could it be some wiring fault with stuff that is wired to the 10-pin connector?  If they're compromising the DC supply on the DCDS, that would drive it nuts.  If all is right there, my next stop is usually the output FET's.

@zhubl posted:

That was my immediate thought when Pat mention the motor terminals but I tried pushing up on that pin it’s locked in place.

Well so this had sat for a year or two because like I said a different repair tech replaced the driver before that questionable day at Lionel 😅. so far I have yet to recently get it to act up minus the continuous flickering markers I’ve put a scope on the marker output unloaded and could see it jumping around of course I don’t know if unloaded really tells me much. I might just leave it on rollers for 30 min one night in conventional and command and see if I get anywhere.

If it runs fine with the class lights disconnected, hard wire those *******s to track power, & never look back,…..The markers on a Kline Hudson tender are hard wired to the track, with just a simple in line resistor from the factory …….

Pat

@gunrunnerjohn posted:

That seems pretty right.  Make sure neither motor lead has any connection to the frame, then it's time to consider the DCDS.

The flickering markers may be a clue, could it be some wiring fault with stuff that is wired to the 10-pin connector?  If they're compromising the DC supply on the DCDS, that would drive it nuts.  If all is right there, my next stop is usually the output FET's.

No obviously pinched wires I did find the 5V from the R2LC loose when I was nosing around no idea if it was originally loose or if it came loose from me poking around.

What exactly is the purpose of the jumper from pin 5-6 on the 6pin power Molex. It appears I can bump that wire while on the bench in conventional and the motor stops. Think I might try replacing the Molex plug.

@zhubl posted:

No obviously pinched wires I did find the 5V from the R2LC loose when I was nosing around no idea if it was originally loose or if it came loose from me poking around.

The 5V from the R2LC is used to power the opto-isolators that feed the PWM speed commands from the R2LC to the DCDS  If that connection was compromised, it could drive the DCDS a bit nuts as far as motor control.  However, I don't think it would have anything to do with blinking marker lights.

@zhubl posted:

What exactly is the purpose of the jumper from pin 5-6 on the 6pin power Molex. It appears I can bump that wire while on the bench in conventional and the motor stops. Think I might try replacing the Molex plug.

That's the eternal mystery!   I've never seen explained what that was for, but I've never seen an Odyssey DCDS installation without it.  Replacing that jumper might not be a bad idea.  Getting the pins out of the Molex there usually requires the extraction tool or similar.

The killer is the extraction tool sells for $28, and it's certainly not worth that much!   Before I had one of these, I used a thin piece of steel that I shaped similar to the tip of the tool.

Here's Rod Stuart's excellent page on the DCDS connections from his Motherboards document.

That 6 pin connector can have bad connections.    Worth examining pins and the connector terminals.  G

Well I’ve redone the pins for the DCDS (didn’t have the correct housing so here goes another DigiKey order 🤦🏻‍♂️) I’ve just let it run on rollers for probably 2 hours with no issues minus the stupid flickering marker lamps. I’m thinking I’ll get the housing and get it on the club layout with a load and see how it does. Any other bright ideas with the marker lamps besides wiring them direct to track power?

Naturally after I post I got it to act up. I noticed after each time it stopped it was like it was a brand new day but the marker lamps never completely turned off. I plugged in the head light and confirmed it would go out when the the motor stopped with the cab light powered straight from the track it stayed on so it’s almost like the R2LC is going flaky?

I tried a new R2LC with no issues and switching back to the original I now can’t duplicate the problem.

I'd consider checking the wiring to the class lights, the fact that you're having problems with a second DCDS suggests to me that there's something besides the board that is the issue.  Remember, those outputs on the 10-pin connector are NOT common in any to the frame!

I'd be temped to just wire up a pair of LED's direct to the 10-pin connector and see if they misbehave.  If they still have flickering, look at the other wiring to the DCDS and see if you have something shorted/cross connected somewhere.

@gunrunnerjohn posted:

I'd consider checking the wiring to the class lights, the fact that you're having problems with a second DCDS suggests to me that there's something besides the board that is the issue.  Remember, those outputs on the 10-pin connector are NOT common in any to the frame!

I'd be temped to just wire up a pair of LED's direct to the 10-pin connector and see if they misbehave.  If they still have flickering, look at the other wiring to the DCDS and see if you have something shorted/cross connected somewhere.

So I did have a different set of LEDs hooked to the DCDS with the same result. Ok now looking for ground faults that I definitely have.

Pin 10 of the DCDS marked GND is hooked to Pin 2 of J4 in the mother board PCB1-10D thus grounding all of the J4 GND pins on the DCDS is this incorrect?

I actually believe there is a ground wire on pin-10 on the 10-pin connector for the Odyssey I DCDS, forgot that one.  That's the one that you have to remove to run with the ERR Cruise-M.  I'm thinking along the lines of the ERR board, so maybe a little different here.