Graham Farish 'DCC Ready' PCB Conversion Method

Mistakes may damage your locomotive, controller or other accessories. Use a multimeter to make absolutely sure you have completely isolated the motor from the track before testing. Always use the Programming Track for testing. Our guides are provided for reference only, and you proceed entirely at your own risk. Unsure about something - try our DCC Conversion Service instead.

This is a general guide to converting Graham Farish locos that are described as 'DCC Ready' but do not have a socket for the decoder. The main PCB inside the loco has seven solder points where the decoder can be attached, which are supplied from the factory with two brass clips joining them so they work on DC.

Most decoders have a switchable negative output for lights. If using a 6-pin decoder, often there is no common positive to connect the other side to. If present, it will be a blue wire (such as found on the Lenz Silver Mini decoders), or a solder pad on the decoder.

If there is neither, you can usually use the 'half-wave' method and link the light positive common to one of the track power connections (red/black). The downside to this is that the light will actually flicker, this may not be visible to the naked eye but many video recording devices will pick it up.

Taken from the official Graham Farish Class 66 service sheet, the solder connections are as follows:

Graham Farish DCC Ready PCB Wiring Guide

Step 1 - Remove Body

Unclip the body by pulling gently upwards, or following the service manual that came with the loco.

Step 2 - Remove Brass Clips

Locate the seven solder points on the main PCB. Remove the two brass clips that are joining the two groups of solder pads together for DC operation.

Step 3 - Attach Decoder Wires

Using the diagram above, solder the six decoder wires to the PCB solder pads as shown. If you have a blue wire or lighting positive common connection on your decoder, connect that also. If not, add an additional wire between the red track pickup pad, and the blue one.

The motor power comes through two copper contacts on the underside of the PCB that press against the two motor contacts. If you wish, you can optionally solder the grey/orange wires directly to the motor.

Step 4 - Test

Test you have no shorts between any of the decoder pins, and that the chassis/track pickups remain isolated from the motor. Test on your programming track, and if all is well, reattach the body.

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