PS2 engine loss of speed control

Well , Before taking it apart try a feature reset. Menu/Advanced/ reset engine/ feature reset..... I'll leave the taking apart part to the tech guys. good luck

Feature reset in both feature and factory reset had no effect. Thank you.

Sounds like a tach board/reader issue. Possibly the tender harness is not connecting one of the wires to the tach board

Tom,

 

When you fixed the solder joint, did you test the engine before replacing the boiler? If you did not, or if you did and the problem was not present, it's possible that you now have a motor or smoke unit wire touching the boiler. Either one could cause a runaway as you describe.

 

I'd suggest test-running the engine with the boiler removed.

Which wire was fixed?  Did any other pads get bridged in the repair with solder?

 

Test continuity of the gray wire in the tender (4 pin smoke or sometimes 7 pin power) to gray wire on tach.  Test orange to orange, and blue to blue.  See if one is open.

 

If not, change tach sensor after making sure gap is good and flywheel stripes good and clean.  G

Thank you for the suggestions. Will attempt these suggestions this weekend. Will post results Saturday evening.

" it's possible that you now have a motor or smoke unit wire touching the boiler. Either one could cause a runaway as you describe."

no wires touching boiler shell.

 

Which wire was fixed?  Did any other pads get bridged in the repair with solder?  No

 

Test continuity of the gray wire in the tender (4 pin smoke or sometimes 7 pin power) to gray wire on tach.  Test orange to orange, and blue to blue.  See if one is open.

 

This test was not done.. Don't understand what I am looking for or checking ? 

 

Last suggestion is to check with Vinny of New Jersey Hirailers in Patterson NJ,

If the problem showed after the repair, the repair did what George stated with a flash over.  You are looking for continuity on the wires mentioned to be sure you do not have an open  (not connected) wire.

Tom,

 

Did you try running with the boiler removed, as I suggested?

To start back from the beginning.  If your engine starts up and stays in neutral unit you apply throttle, most likely it is not a grounded motor lead.  Should test this in both directions without applying throttle.

 

You can always lower your input voltage to the TIU to around 12V to prevent a run away train going too fast and derailing while testing.

 

As far as speed control, if an engine is in neutral and you apply throttle and it immediately goes to full speed the PS-2 board is not getting tach reader feed back.

 

That can be because the reader gap is too large and it can't count stripes.  The flywheel is faded or dirty and it can't count stripes, the tach reader has failed.  The tach reader wiring has an open.  This wiring issue can be at the tach reader (broken solder lead), pinched wire, bad solder joint at the pcb on the back of the steam engine, broken wire lead inside the tether, broken lead inside the tender.  Or a bad chip on the board.

 

The wire feeds are Gray 5VDC, blue PCB Ground (NOT Chassis), and orange tach reader return.

 

 

So the safest way to check the wiring is to remove both shells, plug the harness into the engine.  With the engine sitting on your work bench unpowered; use a meter to measure continuity at the tach reader gray to the gray wire on the tender board connector.  Same for Blue and same for orange.  IF you have good continuity, it is either a bad reader, the gap, or bad circuit board.

 

Since you had some pin solder joints fixed examining the gray, orange and blue to see it cold solder joints too, might fix this problem.

 

I do not recommend testing voltage live, unless you are skilled at electronic measuring.  A slip of the probe and you can easily damage the PS-2 circuit board.  G

Did you try running with the boiler removed, as I suggested?

 

Yes Barry, That's what my first answer was based upon, engine boiler was removed and held away from the driving wheels. Engine comes up in DCS, moving speed up from startup , engine takes off as throttle advanced toward 4 mph

 Does it take off (or move) between 1 and 3 MPH? The spacing between the reader and tape should be about the thickness of an dime. If it's around 1/8" or more, that might explain the take off.

A related question.  Do you hear any chuff sounds when the engine moves in the 1-3 MPH zone or when it takes off?