Heljan 27 will not go

[ColinK]

Hi, I’ve got a couple of Heljan class 27s, on my workbench for my Glasgow Edinburgh push pull project.  Both locos have had a good run on DC quite some time ago without any problems.   I sat down to convert them to DCC about an hour ago.  Before doing so I tried them on my test track.  One runs perfectly, one doesn’t go.  I’ve checked with my multimeter and there is electrical continuity from the wheels to the motor terminals, but the motor shows no sign of life.  I can turn the motor easily by hand which suggests its an electrical problem.  Can anyone suggest whats wrong and how I can fix it?  If it’s a difficult job I would rather send if away.

[csvt2004]

Try powering the motor directly on its terminals. A battery can be handy for that. If the motor works then I suspect its the wheels. There was a batch early on that had poor wheels and replacement sets were available. I replaced the wheels on a couple of mine and have had no trouble since.

 

Richard

[Dagworth]

Edit: read the OP fully before replying idiot!

 

Andi

Edited November 22, 2020 by Dagworth

[csvt2004]

eh? I should read the OP again. No decoder is attached.

 

Richard

[Dagworth]

1 minute ago, csvt2004 said:

eh? I should read the OP again. No decoder is attached.

 

Richard

I did, see my edit

 

Andi

[ColinK]

Thanks. I tried powering  the motor directly and it worked.  The problem appeared to be the two wires from the plug on the circuit board to the motor, one looked a bit suspect.  I managed to get the motor out and replace them with one of the plugs/wires used for the headcode panel light (which I don’t need).  But that didn’t fix the problem. It did create another though, I eventually got the motor back in, but the carden shafts to the bogies popped out.

 

Checking further and power from both rails is reaching the circuit board, but it doesn’t seem to be reaching the black wire on the motor plug (the red wire is OK)  I’ve got as far as I can and I need to find somebody who can fix it, they may as well put the DCC sound in too.  Anyone know who might do that for me?  After my Pacer failure its all getting very frustrating.. 

[csvt2004]

In your picture the DCC blanking plug is missing. Have you tried it with that in ?

 

Richard

[ColinK]

Yes, I only removed it to check the circuits with a multimeter.

[csvt2004]

OK. if you get a small length of wire, you could "strap out" the black wire side of the circuit and that would prove your theory. Touch from the black side of the pick ups to the black side of the motor. If it bursts into life then looks like a high resistance plug/socket.

 

Richard

[cheesysmith]

I would just replace the whole board. If the wire to the motor is ok, directly wire it together using some different sockets so you can change the chip as needed.

 

If you do want to keep the board, ask, some of us have spare boards doing nothing (I know I have, but no idea where they are).

[ColinK]

1 hour ago, csvt2004 said:

OK. if you get a small length of wire, you could "strap out" the black wire side of the circuit and that would prove your theory. Touch from the black side of the pick ups to the black side of the motor. If it bursts into life then looks like a high resistance plug/socket.

 

Richard

Thanks Richard, yes, that works. I hadn’t thought about the plug/socket being the problem.

[ColinK]

I’ve disconnected the circuit board and removed it from the loco.  There is no continuity between any pin on the decoder socket and one of the pins on the plug to the motor.  So presumably that must be the fault.  For DC running I could simply bridge it with a wire - as above I’ve tried it and it works. But that isn’t going to work as I’m going to add DCC sound.  So what I think I need is a replacement circuit board.  Gaugemaster who supply Heljan spares don’t have any.  Has anyone got one they don’t need?

[csvt2004]

This is one of my sound fitted ones. Speaker is encased with blu-tac. If you can repair the socket to plug as you suggested then an installation like this should still work.

 

Richard