Non working Hornby class 43 HST 125

[Dave Cousins]

Hi John

Thanks for your input, shows how much I know about electronics and PCBs, I had not realised they were double-sided.

That’s the confusion, I have soldered the black to J2, not a very good blob of solder granted, I assumed  J1 and J2 were connected. So my PCB is wired correctly according to your additions, would my poor joint have any effect? If not then I'm no further forward.

Dave

[John ks]

9 hours ago, Dave Cousins said:

would my poor joint have any effect? If not then I'm no further forward.

Maybe

 

One way to check the black connection would be to check the DC voltage after the rectifier (4 diodes)

Place your Multi-meter (set to DC Volts) on the PCB pads (between the diodes)  marked (+) & (-) & you should get a reading between 10V & 18V depending on your DCC system

The blue wire is also connected to the (+) & is an alternate place to put your Multi-meter (+) probe

 

 

Don't confuse the Red & Black lines I added as (+) & (-) , they are the DCC in from the rails

As has been stated previously "red & black to the track"

Red is to the RH rail

John

 

[Amand]

18 hours ago, Dave Cousins said:

 I did, however, find the black wire had come away from the chip, now resoldered and I now have lights but still no movement, however with the loco on a rolling road and connecting power directly to the bushes it runs, this applies to both locos but neither will run on the track.

 

 

When you applied power to the bushes was the decoder still wired to the motor? If so then there's a chance that the motor drive circuitry has been damaged beyond repair - the lighting circuit may have survived, if so the decoder could be used to power the lighting circuit in the dummy end unit of the HST.

 

If you follow the link from BromsMods you need the 4th HST item, which is a video. I've scanned through it, just be aware that he uses extender wires which don't follow the correct colour coding. Also the decoder used has a removable harness, so the decoder isn't connected when the multi-meter is being used to check the motor is isolated. 

 

The video below uses a Hornby decoder (same as the one in your HST) but he uses a wired DCC plug, ESU part 51950. I'd recommend using one as it allows a decoder to be changed in seconds, or replaced by a blanking plug for pure DC running. This allows for easier loco servicing and investigation should a loco suddenly stop running.

 

 

[Dave Cousins]

Hi Guys

Well, its been a protracted saga but with all your help, assistance and a couple of new chips, I now have two working locos.

Many, many thanks to you all for your patience with a dumbo but we got there in the end.

 

Regards

Dave.

[grriff]

1 hour ago, Dave Cousins said:

Hi Guys

Well, its been a protracted saga but with all your help, assistance and a couple of new chips, I now have two working locos.

Many, many thanks to you all for your patience with a dumbo but we got there in the end.

 

Regards

Dave.

Thanks for letting us know. It's always good to hear that you got there in the end. Don't do yourself down - we are all Dumbos at some time (but without the ears).

Edited June 23, 2020 by grriff

[Matt C]

A suggestion ?  If the original decoder in the hst has had the motor functions damaged but the lighting circuit still works, is it worth checking the dummy power car to see what chip it has ?  If its a full function chip you could swap it out for the damaged one as it only needs lighting functions anyway. That would give you a chip to use elseware