MTH PS2 3v Big Boy (Premier) no.4014 - runs super fast and does not chug anymore. Why?

Did you try a reset?

Beacause your tach reader failed and the reader is not seeing the motor moving. So it runs at full speed with no chuff

Did you wiggle the tether? Wiggle it a little if you can while running (track power about 10 volts). Could be a bad tether. If not the next thing would be the power supply board.

It’s probably the ps2 board with the tach input that failed. Either way it’s tach related

Well since the engine works and your lucky, not sure how you knew it was compatible, the problem is either the tender tether, or the PS-2 3V board power supply has a failed component.  Can be repaired.   G

Ruled out the board. Tether was brand new. Not the tether. Tried swapping the board and tether with a working board and working new tether. Same symptoms. It’s somewhere between the tether connector and the leads to the board. Which color wires deal tach and and chuff?

The 3 tach wires are typically Blue-Orange-Gray, in order on one end of the 7-pin connector of the smaller board of the 2-board set.

Thank you all for your responses she help.

SOLVED. It was the power board.

So did you effect a repair on the power board?  Just order a new board?  

stan2004 posted:

So did you effect a repair on the power board?  Just order a new board?  

I just swapped it out with a good power board I had and that worked. Also checked continuity in all connections first and reseated the boiler board beforehand. Runs charmingly now...

Right.  But now you have a defective PS2 power board that is repairable - probably $1 in parts though you need to know what you're doing!  Just curious what you plan to do with the board (and no, I'm not fishing!).  It's just that those boards are no longer available but were something like $75 or so.

Right now MTH still has PS2 power boards available.

I actually have a few of the PS/2 power boards, what I need are processor boards!

:-)Laughed when you said it was not board or tether.  Because that would mean nothing is causing it.  Think about it.  Different tender plugged into engine and it worked.  So that clears the engine including the plug in PCB.  So it had to be tender related.  If not tether or board there was nothing else that could be at fault.  Board can be fixed as stated.  New PS boards are $80, repair much less.  G

GGG posted:

:-)Laughed when you said it was not board or tether.  Because that would mean nothing is causing it.  Think about it.  Different tender plugged into engine and it worked.  So that clears the engine including the plug in PCB.  So it had to be tender related.  If not tether or board there was nothing else that could be at fault.  Board can be fixed as stated.  New PS boards are $80, repair much less.  G

I should have specified - it was a combination of the boiler board connections being loose (needing to be adjusted at the connections and reseated) and the power board going bad. When I swapped out the PS2 board originally - I got the same symptom with another board I knew was good, so I figured it was not the board - but along the way I found after that that the boiler board also had a loose connection (after one of my earlier replies). I resolved that and then found that it worked with the other spare board and the other tender I tried first, but I the original board still had the issue - and it was indeed the power board on it.

Also - not that this is an excuse or an attempt at pity or anything, but I am relatively new to PS2 and PS3 board troubleshooting and am learning, quickly, but still learning. I don’t have 25+ years experience yet. Forgive the fumbles in explanations at times, please. I appreciate all the help I receive from each one of you, greatly. 

Just providing more context so other and you can understand.  By boiler board, you mean the small pcb the tether connects to on the engine?  G

GGG posted:

Just providing more context so other and you can understand.  By boiler board, you mean the small pcb the tether connects to on the engine?  G

No, not the tender-tether receiver at the firebox... This Big Boy which is factory PS2 3v (very early run no.4014 from 2004 or 2005 I think) has a board in the center of the boiler that is located right above the hinged part of the engine. The board connects to the smoke unit, some lights, and has a number of other wires (light blue, orange) that seem to effect the tachometer and chuff. If this board is disconnected - the engine behaves as described originally. For instance - if I tested the engine with the shell/boiler and its board completely disconnected it would run erratically and without any response from the tach. There is also a huge blue wire that connects this board to a small pcb on the chassis with a wire nut, in addition to another tether set of colored wires. This is the “boiler” board or “boiler pcb?” I am referring to.

Sounds like a mux board.

Forest posted:

Sounds like a mux board

Forest posted:

Sounds like a mux board.

Right. Mux board. I Always forget that’s what it’s calles.

stan2004 posted:

Right.  But now you have a defective PS2 power board that is repairable - probably $1 in parts though you need to know what you're doing!  Just curious what you plan to do with the board (and no, I'm not fishing!).  It's just that those boards are no longer available but were something like $75 or so.

Stan, I don't see a way to contact you directly and I can't remember if I ever did?

Anyways if you're interested, I have a PS2 3v board set that came out of an abused one gauge Hudson. The boards are in ruff shape and the processor I believe may have been damaged so that it doesn't do it's code well. I broke off a pin connection and also burned a trace to it if I remember right? I was swapping boards out to see which one was damaged and ended up trashing both.

It's here in a scrap pile and I would give it to you for research if you want it. It maybe garbage though? If I remember correctly even G didn't want it?

jwpcfv (at) msn.com

Hi Joe, yes I think we've been in contact offline, but thanks for thinking of me - but I don't need PS2 boards.  I'd think the OP might be interested in your PS2 power board though.  Apparently they're still available for $80 or whatever.  The point I was making is for the problem as described (something with the just the tach circuit), the out-of-pocket component replacement cost on the power-board should be small compared to the labor, shipping, etc. to get it repaired by an MTH service tech or center.

Joe, I always take damaged boards.  Did you offer?  G

DdotCdot posted:

GGG posted:

Just providing more context so other and you can understand.  By boiler board, you mean the small pcb the tether connects to on the engine?  G

No, not the tender-tether receiver at the firebox... This Big Boy which is factory PS2 3v (very early run no.4014 from 2004 or 2005 I think) has a board in the center of the boiler that is located right above the hinged part of the engine. The board connects to the smoke unit, some lights, and has a number of other wires (light blue, orange) that seem to effect the tachometer and chuff. If this board is disconnected - the engine behaves as described originally. For instance - if I tested the engine with the shell/boiler and its board completely disconnected it would run erratically and without any response from the tach. There is also a huge blue wire that connects this board to a small pcb on the chassis with a wire nut, in addition to another tether set of colored wires. This is the “boiler” board or “boiler pcb?” I am referring to.

Ok,  Yes Mux set ups operate a little different. Many have the tach circuit run through them other do not.  You did not mention shell coming off and such.  In a MUX set up, if the engine does work with another mux tender that clears the engine and all internal parts.

Another reason you must be careful when swapping shells, not all engines wired same, and the lack of a buffer in some circumstances will burn up the tach reader when wrong tender attached.  That would be the minimum damage.  Other configurations could do more damage.  Good news is you got it isolated and fixed.  G