Flying & Flashing

Are you running FIXED thru VAR1 (out)?  If so, try running from FIXED 1 IN thru FIXED 1 OUT (thereby taking VAR1 or 2 out of the circuit).  If that works, you've lost whatever circuit inside that enables the ability to run FIXED thru the VAR channel.

Doesn't happen to any other loco.  Happens on all circuits.

Anyone have an easy way to check the sensor?

Robert,

The first thing to look for is a damaged, faded or torn tach tape.

It also couldn't hurt to try a Feature Reset.

RJR,  Does the diesel sounds stay at idle while the engine runs/accelerates without speed control?  If so, the Power Supply board has an opamp that does the speed control and this can be replaced.  Would restore speed control with diesel rev sounds, or it is the tach reader that has gone bad.

The flickering light, is not a symptom I have seen related to speed control.  That sounds more like a AC power issue.  Can you measure voltage and current on the track while this happens?

I would check the 7 pin harness and wiring (Power in and tach wires).  7 pin fully connected.  The red and black wires for AC pickup are fine?  No chassis grounding of red or purple PV wires.

Then try the feature and or a factory reset (If not already done).

If wiring is all ok, the board should be tested.  I can do this if you can't.  G

You can power up the engine and measure the gray to blue wire on VDC setting for 3-5 VDC at the tach sensor.  Then measure orange to Blue while turning the fly wheel to see of you get a voltage flucuation.  Orange is output, Blue is DC Ground.  You also can look at the sensor with a digital camera to pick up the LED light.  If it glows purple you have one half working, but sometimes it still is faulty because the receiver doesn't work.

Other alternative is to move the Power Supply board to another good 3V engine and see if the symptoms follow the board.  G

Thanks, GGG.  I don't think it's a power supply problem; appears to me to be either an quick intermittent short or perhaps the speed control putting on full power and then cutting it.  Happens several times a second.  I don't think the sounds stay at idle, but I'll have to check it again.  Since it happens several times a second, it would be impossible to meausre voltage and current.

I'll have to take the measurements you suggest, when I get a chance.

Thanks, Barry.  The tape was my first thought, but it's crystal clean.

I'll report when I do the test.

Timing tape & reader spacing??  Keep trying a feature reset and maybe a different battery. good luck.

When I say Power Supply, I mean the Power Supply board of the PS-2 and AC power issue.  For a PS-2 to cause other engines/cars on a layout to flicker lights, it has to be reflecting something on the AC input side.  G

Are you using a post war ZW? Maybe try a different handle?

Given the fact that all 19 other locos operate fine on all circuits (even with 3-4 running at a time on that circuit, & that this loco acts this way on all TIU circuits, the problem must be on board this loco.

Since a grandson was wanting to run trains most of yesterday, I couldn't get into this loco other than pull the shell and check the tape---had to monitor operations.

#1 suspect is the tach reader.  I have to do GGG's recommended tests & measure the gap, which shouldn't have changed given the loco has been running ok for 3 years.

A very weird development.  Grandson was operating another MTH diesel, also a 3-volt but an upgrade.  The loco was crawling along (he likes to run it slow) when all of a sudden it took off, with the same flashing lights and the same effect on lighted cars parked on that circuit.

Loco sounds operated correctly, but from both locos I hear a noise, almost like it's in tune with the flashing lights, and similar to the sound one hears when a wheel is off Gargraves track

Feature reset does nothing--in fact, all the sound and speed settings stay the same.  Running under a different TIU also does nothing.

GGG: Looking through a digital cellphone camera, I saw the purple glow.  Between blue & gray, I only get 1.2 VDC.  Between blue & orange, I get fluctuations between about 1.2 & 2.9.

" it has to be reflecting something on the AC input side."  I'm thinking that if the speed control cuts power off and then turns it fully on, the sudden load could cause a brief voltage drop on the track, followed by an increase.  This could also create the noise, as the gears went in & out of slack & the worm caused the armature to bounce up & down.  The loco is going fast, but I don't think it's full speed as if the loco were feeding full power to the motors.

Another possibility, although the coincidence is unbeleiveable, is that one motor in each loco has developed an internal short in one armature pole winding.  That would cause excessive current drain for an instant, and cause the trucks to click back and forth with slack.

What's the tiu's power supply? Happens now with 2 engines and different tiu?

Engine problem? Tiu problem? power supply? I've had problems with PWZWs original circuit breakers and flat rollers on some of the handles especially when the load increases with pass cars and other engines.

I know you're an experienced dcs operator and will get to the bottom of this shortly. loose connection somewhere?

Is it time for a small test track?

Tach readings are OK.  Could this be the TIU acting up.  Loss of DCS signal?  You now have 2 trains behaving this way.  I would take the first offending engine and make a circle track with a small transformer (Z-1000) and test it in conventional.  If it runs with speed control and the diesel sounds rev up and down with throttle, then the engine speed control and tach are fine.  I would then try the TIU with the engine on a small track.

The engine may be having DCS reception issues, but the second engine means you either had bad luck with 2 simultaneous engine failures, or the TIU/ZW is part of the issue.

Could there be loose wiring some where?  G

I tried the engines on two different TIUs ( a G & an H) that feed the layou, with fixed and variable circuits powered by a Z4000, a postwar ZW, & a KW.  Given that the other locos have been running fine, I doubt that the issue is in a transformer or a TIU.  I also tried several remotes.

Note my revisions to last post.

One other oddity is that neither of these locos had been run in several weekts, but every time the layout was on, their tracks were powered, & both batteries keep sound on for about 5 or more seconds.  Yesterday's loco took off when I moved thumbwheel from 0 to 1 right after starting it up.  Today's was running normally and then took off.

What results should I be able to observe after a feature reset, apart from hoping to solve this problem?

I just tried what GGG recommended, running conventional.  Being able to cut the voltage down, I can get it to run slow.  I still get the lights flashing, at a much slower rate, and one can visibly see the loco jerking.  

I unplugged the 5-pin motor plug to isolate the motors, to run resistance tests.  One seems to have slightly less resistance than the other.  However, with a 6-volt DC power supply, they draw 0.26 amps each, & run smoothly.  So I doubt it's the motors or the gears.

Sensor gap is 1mm, which is within spec.

On the loco that went bad this morning, the squealing brakes sound as the train starts moving.

Gregg, each TIU is powered by a separate R-S wall wart.  Since all may layout has toggle switched blocks & has 6 TIU circuits, I have everything off except one 4' section of track, which gives the same effect as a test track.

This is crazy but maybe  try  changing  the engine's  ID Turn off track power for a minute or so. Can you still find the engine? Just another way of testing the battery.

As far as I know a feature reset is the same as a factory reset but the engine's ID doesn't change. Volume seem to be louder. 80% or 100 % I forget.

It's almost like you're dragging a pass car around with a center rail roller disconnected from it mount.

2 engines now having the same problem should be of some  help but it isn't. I'm lost on this one

I had a side conversation with Barry regarding feature reset.  Although, as he mentions in his book, MTH says to press TRK and then softkey 3 to reset all locos on a track, that didn't work.  In his side conversation, he said that method doesn't always work, but to try Menu/Advanced/Reset Engine/Feature Reset.  I did, and this cured both locos.

Thanks very much Barry.

The question now is, what caused these locos to go haywire?????

I assume the speed control was in fact putting on full power and then cutting it, thereby causing the flashing.

Thanks also to all who gave me tips, Bob, GGG, & Gregg.

I knew you'd get it fixed..  great !  I' m assuming the tr soft key is a conventional reset?  or is that proto-1 reset or both?? Barry?

Don't you love it when this forum provides a fix and an item doesn't have to be returned.

Especially when long after warranty has expired.  One loco is an FM 1044 about 4 years old; the other is a 1995 BL-2 which I upgraded many years ago.  As I noted above, the major question is now, what was the cause, and I invite ideas.  I'm sure it will recur.

I'll defer to Barry on the TRK/softkey3 matter.

Gregg,

 I' m assuming the tr soft key is a conventional reset? 

All I was ever able to learn, from MTH, was that it was supposed to reset all PS2 engines on that channel's tracks. Due to varying track topologies, I was never confident that it would actually work. I only mentioned it from a standpoint of completeness. I only discuss Feature Reset being used from the Advanced Menu.

Regardless, nowhere in my book do I ever say to actually use the soft key.  

That is interesting.  I have not seen that behavior before.  To have 2 trains do it is really interesting.

I guess it really should be said up front, but we assume folks try a feature or factory reset.

I always test the engine in conventional first.  Do a conventional feature reset (1W/5B).  At that point if the engine is still misbehaving in Conventional, I can find a hardware issue of some sort.  G

GGG, the feature reset must do something other than affect the settings you have made for an engine, for my settings, as far as I know, were still as set. 

I wonder if a transient spark somewhere on the layout affected some function, rather than a setting, and the reset cleared it.

Note that these locos did the same thing in conventional.