MTH Steam 0-8-0 Motor turns by hand not with power.

Missabe....don't think it is a good idea to apply track power (AC) directly to the can motor to test it, as it operates on DC voltage. The motor will not run, and you can do irreparable damage to it.

If you are going to test a can motor, make sure you have a variable DC transformer to do it with, or have a bridge rectifier inline between the AC transformer and the can motor, to supply a DC current.

Peter......Buco Australia.

Thanks.  I hope I didn't create another problem.  Thanks for info on DC can motors.

Ignorance can be expensive but expensive lesson is never lost.

What Buco said.  Every O-gauge loco made in the last 10 years that I can think of has a DC motor.  Never put leads from an AC transformer to these motors, or you will demagnetize them or burn them out!  Not only that, but unless you also disconnected the motor from the electronics board stack, you were feeding AC back into the motor driver circuit (which probably isn't good! )

If you REALLY want to verify the mechanical integrity of the drive train, you have to disconnect the motor from all on-board circuitry.  Then you can put DC power on the motor terminals.  If you don't have an HO power pack or bridge rectifier handy, you could even use clip leads to a 9V battery.  Watch your fingers because it'll run fast!!  If the motor spins and the wheels turn quietly with ample power, then your problem is electronic and not mechanical.

Look through vent in motor is the winding black looking or copper looking?  Again this can be solder joing on PCB bad, tether bad, or board issue.  G

Buco, Ted & G, I did test the motor as suggested, it's not mechanical.  The tether is good.  The PCB is that on the Engine or Tender?  Is it easy see with a magnifying glass?  Then is there a Schematic for the Board?

@Missabe posted:

Buco, Ted & G, I did test the motor as suggested, it's not mechanical.  The tether is good.  The PCB is that on the Engine or Tender?  Is it easy see with a magnifying glass?  Then is there a Schematic for the Board?

What test did you do to determine the tether is ok? ……tethers are known habitual offenders. The PCB the fellas are referring to is on the engine side. It’s the little socket the tether plugs into.

Pat

What does PCB mean?

@Missabe posted:

What does PCB mean?

Printed Circuit Board

Pat

I did a continuity test on the tender to the (male) plug.  I also (I think?) from the PCB (female) plug  to the front of the motor.  I disconnected when I tested the motor with DC transformer.  Getting old is not good for my memory.

@Missabe posted:

I did a continuity test on the tender to the (male) plug.  I also (I think?) from the PCB (female) plug  to the front of the motor.  I disconnected when I tested the motor with DC transformer.  Getting old is not good for my memory.

If you had all the pins ring true, and you verified that, then yes, the tether “ should “ be good. The female socket ( on the engine ) as George pointed out, can also be known problematic. What is the item # on the box to help you better diagnose this issue? Also, when did the condition occur? Was it running and just quit, or stored for a time, and just never started back up? …….these are the kind of clues we can use to aid in a diagnostic.

Pat

A common issue is a pin breaking the solder joint on the locomotive tether PCB.

I'am going to recheck all the wires that relate to the motor.  The 2 wires from the motor are white & yellow go to the PBC.  They should be the ones too resolder.  If they pass a continuity test I should look at the Board for a burn.  I very much appreciate all your help.

I forgot the Steam Engine is a PS-2 MTH Premier USRA 20-3121-1, 0-8-0.

  Pat it has been running.  At the RH when the whisker track was powered up it took off and as I grabbed it, as it started to derail.

Sometime a bad wire or cracked solder joint will show continuity (no load), but go open when current is flowing (load).  Sounds like you have been chasing your tail on this engine for quite a while.  Send it to a tech who can test boards and swap in tether to determine what is wrong.  G

I spent most of my life working on trucks. In the northeast and you dealt with many wiring issues. I tried to use a test light when chasing out something. Dealt with a lot of corroded wires. Some  would pass an ohmmeter test with no load. But would fail to light a test light.

Seeing the motor on these is a DC motor. Could you simply put a bulb with the proper amperage rating across the 2 motor leads to test the integrity of the tether and the soldered board. At least leave the motor out of the equation. Especially where the poster fed AC directly to it.

What hasn’t been mentioned. Does the rest of the engine function properly. Just no movement.

Well I rechecked everything and believe it or not.  All of you who talked tether problem & PCB.  You were right.  When I started way back, I resolder the white & yellow wires.  I must have continuity tested the PCB solder an not the PCB pin to the motor.  So I hope this solved the problem.

Now I will need to find a 10 pin PCB receptacle.  It would be nice if we could change that system when we eventually up grade our PS-1 locomotives to PS-3.  Again O gauge forum members rate *****.  

@Missabe posted:

Well I rechecked everything and believe it or not.  All of you who talked tether problem & PCB.  You were right.  When I started way back, I resolder the white & yellow wires.  I must have continuity tested the PCB solder an not the PCB pin to the motor.  So I hope this solved the problem.

Now I will need to find a 10 pin PCB receptacle.  It would be nice if we could change that system when we eventually up grade our PS-1 locomotives to PS-3.  Again O gauge forum members rate *****.  

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Pat

Missabe....at least you have a PS2 3V board in that loco (did a quick check when you posted the product number)

I shudder to think were we would be if it was the 5V board.

Hope you get it running as it should....that is a great steam loco.

Peter......Buco Australia.

@Missabe posted:

Well I rechecked everything and believe it or not.  All of you who talked tether problem & PCB.  You were right.  When I started way back, I resolder the white & yellow wires.  I must have continuity tested the PCB solder an not the PCB pin to the motor.  So I hope this solved the problem.

Now I will need to find a 10 pin PCB receptacle.  It would be nice if we could change that system when we eventually up grade our PS-1 locomotives to PS-3.  Again O gauge forum members rate *****.  

Usually, it's just a solder connection to the pins that can be touched up, I rarely have to replace those boards unless someone hacks it up.

This has come up before.  It is not the wire solder joint to the pad.  But the actual pin joint to the pcb.  I usually solder the wire to the pin when I fix these.  At least the back row.  ALSO make sure you do not bridge pads with solder. Short the wrong pads and you can blow the board.  G

How do you solder the pin?  I understand to put the solder point on the pin to heat but won't that melt the PCB?

@Missabe posted:

How do you solder the pin?  I understand to put the solder point on the pin to heat but won't that melt the PCB?

How do you think the soldered the pins in the first place?  No, the fiberglass PCB with the copper traces won't melt.

I guess I'am misunderstanding the pin resolder.  On the top of the PCB 10 wires are soldered.  I continuity checked the pin & (white wire) soldered on the board and it showed no continuity.  The rest showed good.  So I resolded the (white wire) and it still showed no continuity.

It's  between the wires, it's the pins that hold the 10-pin tether connector that break free and need to be resoldered.  Look at the arrows, the pins are under between the two rows of pads that the wires solder to.