HM/DCC P2 Class loco unresponsive after a short run in reverse

[SteelerStu]

I have fitted a new P2 class loco (Lord President) with a new 21pin HM/DCC Bluetooth & DCC sound decoder and used the app on an IPhone to install all the relevant sounds for this class. This has been done on a separate piece of stand alone short track. All seems ok using Bluetooth, sounds and movement. The loco is then set to DCC mode and put on the track and works fine forwards using a Select DCC controller (upgraded to 1.6 in March by Hornby) for a good length of time. If I run the loco in reverse for about 30 seconds it becomes unresponsive and will not stop, it just keeps running. I have to kill the power to stop it. With the power back on it does not respond at all, nothing. If I use the app in Bluetooth mode the loco works. I have reinstalled all the P2 profiles numerous times, reset CV8 numerous times. Nothing seems to cure the issue. every time everything is reset - the same thing happens.

I am pulling my hair out.

[SteveM6]

Possibly a DC runaway. Try disabling DC running in cv29.

[SteelerStu]

Thanks Steve

I want to run it on the layout via dcc not bluetooth

[96RAF]

Just to confirm, you are saying it works fine from the app in both directions for an extended time, but from DCC it only runs forward all the time but backwards control is lost after a short time.

Is app control running being checked on the main track, i.e. using the same track power source - the Select track output.

I would have suggested the reverse half of the motor drive H-bridge was cooking out, but if it works from the app that throws that theory out.

Unfortunately this week all the gurus at Hornby are away for various reasons so there is no one to ask to get a quick answer.

[SteveM6]

Thanks Steve

I want to run it on the layout via dcc not bluetooth

 

 

Notwithstanding Rob’s subsequent answer, changing cv29 to disable DC running will still allow you to run it from your standard DCC controller. It will just stop the decoder shooting off uncontrollably if it mistakes a spike for a DCC signal.

[SteelerStu]

Hi there

understood 👍

just to let you know I have spoken to hornby and I have returned the loco as is for them to sort out as they can’t understand the issue.

thanks

[ColinB]

Some people are going to hate this response but what I normally do is replace the decoder with a different type from a different manufacturer and see if the fault is still there. I very rarely see DC runaway, some decoders seem more sub sceptical to it than others. The other thing it could be is the Select getting confused. I recently had a loco that I had been running for about an hour to run it in, when the loco suddenly lost its sound and control from my DCC controller. It worked out that my DCC controller had got itself lost and wasn't sending out the right commands. I assume your track is clean, normally I get these sort of faults when my track is dirty.

[SteelerStu]

Thanks Colin

the track is fairly clean as I only recently cleaned it.

I am told it could be interference from my Wi-Fi on the same frequency. The loco is back with Hornby for a second time.

[96RAF]

WiFi interference of the Select is highly unlikely. The Select does not have any radio capability. I have my controllers on a bench right above a tower PC, alongside the monitor and with a mains powerline adapter feeding my internet in right next to the bench and those things are radio noisy, but I have had no problems either with the dcc controllers or the app devices.

Try resetting not the decoder but the Select - instructions in the v1.5 manual. Sometimes a controller can get out of kilter and a unit reset fettles it.

[SteelerStu]

I had the my select upgraded by Hornby in March to 1.6 and they say it should be fine as is. Will look into resetting it.

thanks

[SteelerStu]

I had the my select upgraded by Hornby in March to 1.6 and they say it should be fine as is. Will look into resetting it.

thanks

[SteelerStu]

Hi

Thanks for all your feedback. I now have the loco back from Hornby for the 2nd time and they are saying there is no issue with it. They say the problem is that my track layout is to large for just one power supply and that I need to re-wire in a STAR format or similar to a RING MAIN supply as the loco is losing the signal from the controller. So looks like I will try the STAR format. I have not run the loco as yet and will try it when I have re-wired the layout. I do not however have any issue with any other DCC sound loco !!!!

[P-Henny]

IMPORTANT INFO FOR ST, PLEASE READ.

Do you have any power tracks (tracks not the push in connectors) with buff coloured press buttons. If you do, then these are Analogue power tracks and need their internal suspression capacitors removed after flipping up the cover between the rails.

Analogue power tracks are known to make very strange things happen with DCC fitted locos. And what you describe is very strange and falls into that category. Not all decoders are automatically affected, and it is possible for one decoder in isolation to exhibit strange behaviour whilst others don't, but more normally many locos are more usually affected.

This capacitor issue has absolutely no impact on any decoder controlled by the Bluetooth APP as the decoder commands are not going through the power tracks. This being the reason why I am suggesting that an errant capacitor in circuit may be the cause of your issue.

A track power capacitor issue would also account for why Hornby tech can find no fault in the loco.

The clip in Analogue power connectors (R602) also need to be modified for digital working, but these are harder to identify visibly as they do not have buff press buttons. The press buttons on the digital power tracks are usually either dark grey (borderline black) or green. Access to R602 capacitors is achieved by prising open the clamshell plastic cover housing. The R602 has, I believe, R602 embossed on their undersides.

Every Hornby track connection relating to power should be checked for the presence of this capacitor and removed if found present. This includes Hornby R8201 Link Wire track connectors, even though some documentation states these are digital compliant, they are not and the documents in question have a mis-print that Hornby have previously acknowledged.

[ColinB]

From my experience SteelerStu, I have had a lot of issues with the HM7000 with weak signals with the loco stopping on parts of the track that my other sound locos don't, I have mentioned it many times. I normally run Zimo, Loksound and TTS. I don't know if any of the fixes to the HM7000 Hornby are going to fix the issue. The loco that had the issue was a West Country with pickups on loco and tender. My layout is about 16 foot by 10 foot that I split my layout into switchable sections as we used to in the old DC, so it is easier to isolate faults, so I don't know if that is a way forward.

[Fishmanoz]

If it were me, I’d be waiting for the new sound profiles to become available before I did anything. They may fix the problem.

They will not solve the analog connector capacitor across the track connections problem though. To run with the Select, any and all will have to be removed.

[ColinB]

Ok, if you are quite competent at changing decoders, take one out of your locos that gives you no trouble, a sound one so it is drawing the same amount of current and see if it fixes the issue. I bet though that all your other decoders are 8 pin, which is why you haven't tried it up to now. The other thing is to buy yourself a 21 pin decoder, Train O Matic ones seem quite good (the wonderful Jenny Kirk recommends them, but in all seriousness they are ok), replace it and see if the loco goes backward. If it does then send the HW7000 back to Hornby and tell them the fault. I did have one Zimo decoder that would only go in one direction it was a fault in the driver blown up by incorrect wiring on a brand new Hornby loco. Hornby could fix the fault in their next software release but if nobody has told them about it they won't have and it doesn't sound like a software fault as everyone would be complaining. The other issue I have had with HW7000 is that the 21 pin decoder doesn't lie flat which means it doesn't sit on the connector properly, which means it doesn't make a decent connection which would mean it would work intermittently. Perhaps when it goes backwards it disturbs it. These are ideas what you could try, you know you layout is ok, if capacitance was an issue none of your other locos would work properly which I assume they do, so it is either the loco, which I doubt especially as Hornby checked it or the HW7000.

[P-Henny]

if capacitance was an issue none of your other locos would work properly.

 

 

Colin, you admitted in previous recent dialogue that you don't read EVERY thread posted ....... I do.

There have been posts published where ONLY one loco exhibited issues that were fixed by removing power connector capacitors. So although rare, it IS possible.

At least give the OP the option to check, as capacitors could be the cause of the issue. If the OP doesn't check because you have poo pooed it, then he may miss a solution.

[SteveM6]

Is ‘HW7000’ a successor to the HM7K system?

[ColinB]

So correct me if I am wrong HM7K = HM7 * 1000 = HM7000. Anyway what I did was put my HM7K into my Thane of Fife and reprogram it with the P2 profile, I think I got the same result. Sound but no movement, pushed it along a bit and it sorted itself out. I will do a lot more checks in case there is something else causing it. It was at really low speed in reverse.

Trouble is the P2 has really large wheels and weird geometry on the wheels so it is pretty easy for it to get stuck. Incidentaly, I checked the timings, 20 seconds to move the file from webpage to phone, about 26 minutes to load the profile as it indicates SPIROM with a bar graph. Unfortunately did it twice because it is so easy to hit the wrong soft key, and the the timings repeated themselves.

Right a question for you on the information pages there a list of software versions, does this change with each software profile that is loaded. I can probably check but I can't be bother to wait another half hour to load another profile. He could well have a capacitor clip but he can check it, as he is using a Select I imagine he is using the clip that came with it. Personally I solder directly to the rails.

[P-Henny]

Colin, I mean no disrespect, but are you by chance Dyslexic? This is a genuine question as it would go some way to explain your posting history of misinterpreting posts.

In your earlier post above on this page you wrote HW7000 three times instead of HM7000.

It was your substituting W for a M typo (I assume it was a typo, once could be considered a typo but 3 times in same reply) that SteveM6 was querying in his cryptic reply that obviously went straight over your head without registering.

[ColinB]

Yes, it is a bug got the effect going forward, loco making lots of noise but the wheels aren't turning, in my case it happened just after a dirty piece of track where it reset itself and then go confused after it had moved a little distance. I would suggest adding a "power pack" which I think will probably fix it. So it could be low signal, I will try the same test with my Lord President fitted with a Zimo decoder.

[96RAF]

Yes, it is a bug got the effect going forward, loco making lots of noise but the wheels aren't turning, in my case it happened just after a dirty piece of track where it reset itself and then go confused after it had moved a little distance. I would suggest adding a "power pack" which I think will probably fix it. So it could be low signal, I will try the same test with my Lord President fitted with a Zimo decoder.

 

 

Ref Paul’s post above - tongue in cheek are we talking about you or the locos.

[ColinB]

No, not dyslexic, but thanks for the compliment, I think seeing I spent most of my life writing technical reports someone more important than you would have noticed. Plus I had to do a dissertation for my CEng so I think they would have noticed too. I probably hit the wrong key or was too busy trying to get the content down plus I figured you would all know what I was talking about. I probably forgot to proof read it. To be quite honest does it matter but I forgot to you it does. Thanks for the concern though. So lets get this straight you criticise HM7000 instead of HM7K, and a W instead of an M and you wonder why there aren't many people posting. I am seriously thinking why do I bother? Have a nice evening.

[ColinB]

So 96RAF what you on about, I try to help someone and get a load of abuse from you and your mates. I am not dyslexic, just very lazy when writing things down. It is no wonder there is a shortage of decent posts. I don't care whether it is a bug or not, it doesn't affect me, I don't run my locos at that speed and I decided long ago not to buy the product, but I have one so I can test things out which I did in this case. Ignore it if you want, if it becomes an issue for me which I doubt it will, I would report it directly to the manufacturer as I did with a fault on the new Zimo decoder. I do find it quite amusing though. About time to lock the thread.

[Fishmanoz]

Wouldn’t it be a good idea to get the OP a solution to his problem before any thread-locking is considered?