Are my decoders faulty?

Airbuspilot

Airbuspilot

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I am working with 2 locomotives one of which was thought to be analogue but actually has a decoder, the other was dismantled (Heidi steam loco) when I first became involved and I reassembled it. Both run well on a DC track so I assume the motors are in good condition. Heidi had extensive sounds, smoke etc. the other doesn't seem to have a speaker but I have not dismantled it fully so I am not certain this is correct.

Both Locomotives respond to CV read and write requests and they judder with each selection which presumably means there is a connection between the decoder and the motors. On the programming track the lights work correctly with direction. When placed on the main track neither of them will run, I can control lights but no sounds. Prior to Heidi being dismantled the sounds, smoke etc. worked correctly.

My question - do I have a programming problem or a faulty decoder problem?

In an earlier post Phil S identified the decoder in Heidi and I have a replacement, I don't know which decoder is in the other locomotive but Jon identified 2 of 55020 in a similar locomotive.

Robin
 
If you read CV1 (short address) but the loco does not respond at all.. Then you need to check CV29 to see if the loco has been set to a long address.

If the loco lighting is changing direction, but the loco will not move, then it could be settings for starting voltage, top-speed, or a 'custom' speed curve is selected, but there are no settings for the individual steps in the decoder..

The fact that they run correctly on DC, leads me to suspect a configuration problem.

PhilP
 
Make sure to check the switches in the cab. One setting parks the loco with lights and sound on but the loco will not move. I'm not sure how this affects the loco on a programming track. LGB loco cab switch settings are common problem that we all tend to forget about!
 
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Thanks for your comments, for Heidi the MX 32 was set up with address 44 and confirms with CV read on program track, the other locomotive was set to address 1 which I reset to 99 along with the change on MX32.

CV 29 was 6 for the electric loco, I don’t remember the CV for Heidi But I think the same. Heidi CV no 1 = 11.

Starting speed and max speed were set to max on the electric loco, again I don’t remember the CV‘s for Heidi.

The cab switches are a possibility, I will need to check. I thought the cab switches were for DC operation and were ignored for DCC, is this not correct?
 
Correct, the function button operates the lights on both locos but I have no movement when I operate the slider in either direction. It is certainly possible the cab switches have been moved, I will need to look at that. With CV 29 set to 6 I believe the start and max speed CV’s 2 + 5 are active? I think both are set to max value of 255 But I will need to check.

I thought the switches were for DC only operation?
 
So a stock decoder installation in this loco could burn out the bulbs after a reset?

Or perhaps this is not a stock installation?

I guess I would suggestion a default procedure for EVERY loco you encounter.

First, I would try to physically verify if there is a decoder or not.
Next I would put it on a programming track and try to read it.
If I can read it, getting the manufacturer ID and version, cv1 and cv29.

Trying for the quick win without the foundational information has not succeeded for you yet. Using the same step by step procedure will make it easier.

I've been in DCC for a long time, I still start from the beginning every time.

Greg
 
Airbuspilot said:
Thanks for your comments, for Heidi the MX 32 was set up with address 44 and confirms with CV read on program track, the other locomotive was set to address 1 which I reset to 99 along with the change on MX32.

CV 29 was 6 for the electric loco, I don’t remember the CV for Heidi But I think the same. Heidi CV no 1 = 11.

Starting speed and max speed were set to max on the electric loco, again I don’t remember the CV‘s for Heidi.

The cab switches are a possibility, I will need to check. I thought the cab switches were for DC operation and were ignored for DCC, is this not correct?
Click to expand...
By starting speed, I assume you mean CV2, starting voltage. This should be low, not max. the default is about 2. What equipment are you using for programming?
 
My mistake in previous message the starting voltage CV 2 on both locos is 1 not max as I stated, max didn't make sense. I will go over again tomorrow, weather permitting, and check the switch positions and CV's again, starting with the manufacturer CV 8.

I am using Zimo MX 32 FU for programming.
 
Try increasing it a little. Massoth suggest this if a loco does not move on the default, which is 2.
 
I understand fine tuning CV2, but I have a hard time believing that any setting of CV2 would STOP it from moving... I know too high and it will take off too fast.

But a setting that does not allow it to move, I think that is impossible from the definition of the CV...

Now, CV5, sure...

Greg
 
I managed to look at the above suggestions yesterday. Staying with the Heidi loco as this is the one that I can confirm was operating prior to being disassembled.

The cab switches need to be in position 2 or 3 for the motor to run, I tried both with no effect.

I read CV's :-

1. 11
2. 5
3. 15
4. 15
5. 255
6. 0
7. 18
8. 131

17. 192
18. 128

28. 0
29. 6

I don't understand why long address doesn't read 0 as I have address 11 in CV 1,

I thought CV 6 could be a problem as MID speed could limit all speeds to Zero, I'm just guessing here.

I tried to change CV 6 to 255 but it refused to change. If I understand the decoder is a TRIX version 18 ?? Is it possible the decoder doesn't have the capability for mid speed (possibly very old version?)

I managed to change then change back other CV's with no problem

255 sent to CV 6 but no ACC

No 7.JPG



CV 6 read after SENT message

No 8.JPG
 
OK:

You can have THREE addresses stored in a modern decoder at the same time, (short address, long address and consist address)

what is important is which you are using.... the choice between long or short, i.e. which is IN USE, is CV29, bit 5 determines which is in use.

on cv 6, it depends on the decoder, but for many decoders 0 or 255 means it is "off" or does not matter. This is in the particular decoder manual. Also some decoders might read back but not use it, again the authority is the decoder manual.

Remember you can always ATTEMPT to write a CV, whether that CV is supported by the decoder is a different question.

Greg
 
Have you tried to set the MX32FU to 28 speed steps for each loco number with the 55020 decoders? 55020 does not do 128 speed steps.
 
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