R955 (HST Power Car R370)

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R955 (HST Power Car R370)

Postby James123 » Fri Mar 16, 2018 12:02 pm

I have just acquired a second hand HST.
It will not run when battery is touched on the wheels or motor. I opened up the body and found a PCB board inside. This has red black and green wires coming from it. Red goes to the right hand side of the motor, green goes to one front bogie terminal, black goes to the motor terminal behind the red one. A brown wire goes from this latter terminal to the front lights as does another brown from the second terminal on the front wheel bogie.
I have never seen this in an HST.
Does anyone know why this would be fitted and why the motor does not run when a battery is touched on the wheels or terminals?
hst 4.jpg
HST 3.jpg

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Re: R955 (HST Power Car R370)

Postby End2end » Fri Mar 16, 2018 12:22 pm

I could swear thats not a DCC decoder. That looks like an old Hornby Zero 1 chip.
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Re: R955 (HST Power Car R370)

Postby Bufferstop » Fri Mar 16, 2018 1:04 pm

Three wires, Zero One or one of the other proprietary multi train systems of the same vintage. There will be one wire from the wheels direct to the motor, the other goes via this board. Take it out preserving as much of the three wires as possible, make a new second connection between wheels and motor, then see if you can flog the module. There's a market for them as there are still some diehards using the system.
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Re: R955 (HST Power Car R370)

Postby Mountain » Fri Mar 16, 2018 4:10 pm

It is a zero 1 chip. I could do a swap for it with something as I have a zero 1 controller, slave and several chips (Decoders) for sale and I can add it to them.
When removing the decoder, there is normally a little blue capacitor thing that goes with it. Not sure if it is for TV suppression purposes. I can't see one on your pics though.

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Re: R955 (HST Power Car R370)

Postby Flashbang » Sat Mar 17, 2018 1:52 pm

Its a Zero 1 or MTC decoder that only works with that system. It will not work with DCC systems.
The question is how is the loco is to be run when that decoder is removed? DC (Analogue) or DCC (Digital) as it will effect the way the loco and lights are rewired.
If returning it to just DC operation, remove all wires from the decoder where they connect to the loco and remove decoder. You now need to connect the right hand motor terminal to the rear bogie wheels, but to only one side of these wheels. Normally the lead Hornby used has a small spade connector on both ends, so you may have to solder the wire? It replaces the green wire on the rear bogie and goes to where the red wire was removed from on the right hand motor terminal. Leave the brown lighting wires as they are. They only light in forward direction.
This is the service sheet I believe... http://www.hornbyguide.com/service_sheet_details.asp?sheetid=37
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