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Discussion Starter · #1 ·
I have chipped an old Hornby 125 (made in GB) with a TI chip. I have another CL43 in GNER, with made in China, to chip. I am having major problems with this one. It appears to use the metal body and has a metal bracket that holds the spring and brush for motor. I have insulated the bracket and wired to the spring, red to track pick-up and orange to spring. When I tried it, it shot off the programming track. When I put it back on the T1 glowed well in the middle and burnt the encapsulation covering the decoder. I noticed that the orange cable had got caught in the gear wheels but these appear to be plastic. The metal chassis is connected to the track (red pick-up).
I plucked up courage and fitted a second decoder making sure that the wires couldn't snag. This time as soon as you put it on the track it jerks slowly along whatever the ESU is set to. I have placed the chip back into the other CL43 and it works fine.

I have used a meter to show that the brush pick-up is isolated and checked the wiring connections more than a dozen times. I have left the suppression cap in. I have used loco's I have 2 off and using the same settings for each have tried them both with suppression and then one with and one without. I couldn't see any difference. This may be because I only have a 5' programming track as still making baseboards for my layout.

Any ideas/help gladly received.

Ian M
 

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Discussion Starter · #3 ·
I have tried a simpler way which avoids any drilling. The only problem I could think of was if the spring is able to short out to the chassis. Brians method would also have this problem I believe as he is isolating the metal strip so this conducts to the spring and then brush. If this is near to the metal chassis it could short. Will try and see if the spring is in an isolated hole.
In soldering to the spring I have soldered across the spring to avoid soldering one sided and putting stress to that one side.

Ian
 

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Discussion Starter · #4 ·
Found the problem. That blo**** capacitor. Once removed runs fine. Bang goes all that time playing to see the difference with and without it in. They are going to be removed from all my chipped loc's now.
 

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Hi enM

Glad you got the problem sorted, Capacitors cause all sorts of problems with motor control on DCC

The better(or finer) the the motor control of a decoder is - the more the capacitor interferes with it.

or

Cheap chips - not much problem - but not much control

Regards

Zmil
 
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