Williams Reverse Board

[EIS2]

I am gutting an MTH PS2 engine with defective electronics and replacing the electronics with a new Williams Reverse Board with Lockout (Item No. 00249).  There will be no sound modules installed.

The instructions are not very clear.  For example, the instructions state “If you are mounting horizontally, unscrew the mounting bracket.  BE SURE TO NOTE THE POSITION OF ANY INSULATING WASHERS. Remove the bracket and use this bolt, washer, and nut to mount to the floor.”

The bracket was not mounted to the board, so I don’t know where the insulating washer should go, nor which of the two holes in the board, as shown in the photo below, is the mounting hole for the bracket.  One hole has a silver ring around it, but it doesn’t appear to be electrically connected to any of the traces in the circuit board.  The other does not have the silver ring.  Which is the correct mounting hole?  I assume the insulating washer should go between the screw head and the circuit board.  Is that correct?

Additionally, the instructions say nothing about where to connect the headlight wires.  Where should the headlight wires attach?  I want the headlights to remain on in neutral, so I can’t connect the wires to the motor power leads.  I think the MTH PS2 engines used 5v bulbs, so I will add a 5V voltage regulator, unless there is already a 5v source on the circuit board.

Since two identical wiring harness to the two motors are provided, do I need to connect the two red wires (one on each harness) to the roller pickup and the two black wires to the metal frame, or will connecting just one of the red wires to the roller pickup and one of the black wires to the metal frame suffice?

Additionally, there is a very, very loose part shown in the photo.  It is just dangling by one of the electrical connections.  The marking on top says CS, 4.7, 35V.  It is surface mounted.  Is there a way to reattach it?  Will the heat from a solder gun damage the component?

Thank You...

Earl Staley

[lionelsoni]

The loose component is a (probably electrolytic) 4.7 microfarad capacitor with a 35-volt rating.  It should have two connections to the printed wiring, and the polarity matters; so note its orientation before it comes off completely.  The capacitor won't be harmed by resoldering it, but it is easy to detach printed wiring by overheating.

In fact, that may be the only problem:  If the foil is still attached to the capacitor terminals, just glue the capacitor and foil back into place.

"CS" is actually "C5," which just means that it is capacitor number 5 in the circuit.

 

 

 

 

[EIS2]

lionelsoni

In fact, that may be the only problem:  If the foil is still attached to the capacitor terminals, just glue the capacitor and foil back into place.

"CS" is actually "C5," which just means that it is capacitor number 5 in the circuit.

 

 

Bob,

Thank you for your reply.  The loose capacitor has now come completely off the circuit board.

I don't think the CS is C5, because the CS is on top of all the capacitors, as you can see on the other larger capacitors in the photo.  However the capacitor is in fact C5 from the markings on the circuit board. 

I assume that the black mark on all the capacitors represents polarity, probably the negative terminal.  Regardless, I can see, by the markings on the circuit board, how to orient the capacitor.

Resoldering is not an option because there is an electrical connector just to the left of the capacitor as shown in the photo which prevents any access to the left solder joint.

I have never heard of gluing an electrical component to a circuit board.  What type of glue should I use to maintain electrical connectivity?  Is the procedure to just add glue to the tabs and circuit board and set the component in place?

I do not know the purpose of the capacitor, but since the reverse board also has many unused connectors, I thought the reverse board might work without the capacitor.  So I hooked the power leads to the track and the DC leads to the engine motor using jumper wires and the motor ran fine. 

One thing I did notice is that the reverse board starts up in neutral rather than forward, as all my other Williams engines do.  Do you know how to set the board to start in forward?

Thanks for your help...

Earl

[lionelsoni]

I didn't see the "CS" on that capacitor and didn't look at the others.

I'm afraid that, if the capacitor does need to be reattached, soldering is about the only option.  The gluing I proposed was just to make the thing mechanically secure and prevent any flexing of the connection; it's unlikely actually to make an electrical connection.

Can you solder a couple of wires to the board, to connect up the capacitor an inch or so from its proper position, then glue it to something that will immobilize it?

I'm sorry that I don't have any insight into the circuit.

[EIS2]

lionelsoni

I'm afraid that, if the capacitor does need to be reattached, soldering is about the only option.

Bob,

Thank you for the reply. 

The only way I can even see the connection is through a 10x magnifier, so soldering is out for me.  When I looked at the connection with the magnifier, it appears that the soldering connection did not break.  It appears that the circuit board trace was actually ripped up and the trace broke, which released the capacitor. 

Since the box that the reverse board came in was not damaged, I think the damage to the circuit board occurred before the reverse board was packaged.

  I decided to return the board.  The online store where the board was purchased agreed to replace the board and paid for the return shipping.

Earl