Class 350 Desiro.

Post all your DCC only problems, solutions and discoverys here.
User avatar
Peterm
Posts: 1428
Joined: Fri Nov 09, 2007 1:26 pm
Location: Bribie Island. Australia

Class 350 Desiro.

Postby Peterm » Sat Jul 27, 2013 7:04 am

Third forum I've put this on... hope I can get some resolution to a problem. It's long but please bear with me.
A friend of mine bought a Bachmann 350 Desiro. I thought it was DCC fitted but it had a blanking plug. Anyway, he put in an ESU 21 pin decoder, and then asked if I could fit an ESU sound decoder (Loksound V4) which I did. I fitted it the right way up. It was such a simple job that I can't work out what's gone wrong, but since fitting it, the interior lights, cab lights and head/tail lights don't work. I tried the original decoder and still the same... no lights. I put in the blanking plug and tried it on DC, still no lights. I then put back the sound decoder getting the same result. After double checking which CV to reset, I set CV8 to 8 and hey presto, still no lights and now the sound seems to have re mapped itself. F2 and F3 were the horns, but now F2 is empty and F3 is doors opening and closing. Putting a small voltage direct to the interior lights proves that they work, but there's nothing coming up the contacts inside the carriage. There's no current going through the coupling bars which are fitted with the contacts facing up. I did find a wire had broken off it's solder joint at one of the coupling bars and soldered it back on, but I do wonder if this could have caused some damage before I found it by shorting out. The thing is, it drives just as it should, but the decoder seems to have scrambled itself. I've tested the diodes on the pcb with my multimeter, also the resistors and they all seem ok. I've also checked for continuity on the pcb, but this is not that easy because it's double sided and it's hard to tell if you're actually testing the correct track. I think I've covered everything I've done, but now I hope someone else can come up with something.
Pete.

User avatar
Peterm
Posts: 1428
Joined: Fri Nov 09, 2007 1:26 pm
Location: Bribie Island. Australia

Re: Class 350 Desiro.

Postby Peterm » Sun Jul 28, 2013 10:31 am

No takers ?
Pete.

User avatar
Roger (RJ)
Posts: 1352
Joined: Tue May 29, 2007 2:59 pm
Location: Nottingham, UK.

Re: Class 350 Desiro.

Postby Roger (RJ) » Sun Jul 28, 2013 10:46 am

It sounds as though you have two separate problems. One is the lights not working and the other is the sound decoder.

I would tackle the lights first as they don't work with a decoder or without, therefore it's not a decoder fault. Possible causes would be broken wires, poor contacts disconnected plugs etc

Do your fault finding on dc if you can so that DCC doesn't confuse the issue.

I don't have any knowledge of this particular model and can't see a service sheet anywhere so I'm unable to give any further advice. Maybe a few good quality pics of the insides of the model would help diagnosis.
If at first you don't succeed - cheat
Anyone who is willing to stand for political office isn't fit to be in political office

https://www.modelrailwayforum.co.uk

Rog (RJ)

User avatar
Peterm
Posts: 1428
Joined: Fri Nov 09, 2007 1:26 pm
Location: Bribie Island. Australia

Re: Class 350 Desiro.

Postby Peterm » Mon Jul 29, 2013 1:05 am

Hi Roger.

I've tried it on DC; and with no decoder in to save doing anymore damage I've used the multi meter to check the pcb and wiring, result, nothing. I've also looked for a service sheet but couldn't find one. I emailed Bachmann who couldn't help either.

If I was ham fisted, a total novice, or it was a really hard and complicated job to do the install, I'd probably say that I'd done something wrong, but it's a really simple job which takes less than 5 min's. To make matters worse, it's not mine.
Pete.

User avatar
Flashbang
Posts: 3258
Joined: Thu Oct 18, 2007 1:07 pm
Location: SE United Kingdom
Contact:

Re: Class 350 Desiro.

Postby Flashbang » Mon Jul 29, 2013 10:59 am

Hi Peter
Found this fitting guide on the Bromsgrove Models web site. http://clarahost.clara.net/www.bromsgrovemodels.co.uk/bachcl350dccinstr.htm
I assume yours is the same?
Looks simple enough with no need to remove the body from the chassis. Excellent progress by Bachmann.

Last sentence states...
In order for the lighting to work it is essential that the carriages are arranged in the correct sequence, using the letters A to D which are marked on the underside of the carriages.

Stab in the dark time now and also worth checking, if all the units are coupled together correctly...
Check all the 21 pins the decoder plugs into are correctly orientated and none are bent over or worse broken off.
Check the dc blanking plug and the the DCC decoder are fitted the correct way up - I know they shouldn't go in the opposite way around, but if forced....

Good luck.
[Image << Click the Icon to go to my website
Broken? It was working correctly when I left it.

User avatar
Peterm
Posts: 1428
Joined: Fri Nov 09, 2007 1:26 pm
Location: Bribie Island. Australia

Re: Class 350 Desiro.

Postby Peterm » Tue Jul 30, 2013 6:16 am

Thanks, but unfortunately I've done all that. This is why I'm having such a struggle, because it's such a simple install. I did have to take the body off because I fitted a 20 x 40 speaker, but touched nothing that I would have damaged. We're waiting on a reply from Legomanbiffo re: the loss of sounds and scrambling of functions.
Pete.

User avatar
Bufferstop
Posts: 10866
Joined: Thu Mar 11, 2010 12:06 pm
Location: Bottom end of N. Warks line

Re: Class 350 Desiro.

Postby Bufferstop » Tue Jul 30, 2013 9:54 am

Peter, not any real suggestion, but another series/method of assessment.
"If the sequence or timing of output events is not what should be expected, then fully check the input conditions and events before and during operation. Then if all are found to be correct the device is at fault."

I once came upon some machines which were "going crazy" in the words of the QC inspectors. Doing thousands of pounds of self damage in the first few seconds. Basic test with field technician kit showed no abnormal values. An oscilloscope showed the 12v DC line to be almost totally unsmoothed to the point that all driver circuits were attempting to switch 100 times per second, and managing to do it once every few seconds.
The failure of diagnosis was the assumption that a correct meter reading meant a correct input. The cause of the fault, the screws which held the tags onto the terminal posts of the smoothing capacitors were 1mm longer than spec, bottoming in the blind holes before the tag was gripped tight.
John W
aka Bufferstop
Growing old, can't avoid it. Growing up, forget it!
My Layout, My Workbench Blog and My Opinions

User avatar
Peterm
Posts: 1428
Joined: Fri Nov 09, 2007 1:26 pm
Location: Bribie Island. Australia

Re: Class 350 Desiro.

Postby Peterm » Tue Jul 30, 2013 11:08 pm

Hi John.

I think I understand what you're getting at, but I have to ask the question. How can I (without doing damage) check a decoders components for correct input ? You see, I'm bumbling along here and simply checking resistors and diodes on the pcb of this emu. I don't want to try checking these tiny diodes/ resistors on the decoder in case that in itself causes damage. I've checked and checked visually for physical damage everywhere including screws, etc. I don't know anyone that can test the decoder, so it might have to come back to Legomanbiffo and see what he can find. Even if it's faulty I'd be reluctant to simply put it, or a new / repaired one back in without the pcb being given the all clear by an expert.

Sorry if I've totally misunderstood your reply, feel free to give me a thick ear if I have. :wink:
Pete.

User avatar
Bufferstop
Posts: 10866
Joined: Thu Mar 11, 2010 12:06 pm
Location: Bottom end of N. Warks line

Re: Class 350 Desiro.

Postby Bufferstop » Wed Jul 31, 2013 10:41 am

You are dealing with a device within a device, so the first step is to check the voltages around the outer device (the PCB and components) treating the whole combination as one entity. If the inputs to that are ok, then check the voltages on the decoder pins. If you prove the decoder itself to contain a fault you accept that there's not much you can do about it. So if the fault appears to be within the PCB, how will you proceed? If you suppose that you can identify a faulty component on the PCB, do you have the knowledge and the physical ability to replace that component? The answer is likely to be no. It may as well be another solid block. Repair by replacement is the logical answer, as long as it doesn't become diagnosis by replacement. If you can say I've done all that, then you've hit one of the constraints of this diagnostic philosophy.
By the way it was imported along with much of the gear by the American military, it bore the acronym FIMS. We all swore that it stood for Fault In Machine Somewhere. We hated to admit that it was more important to return the machine to working status than it was to satisfy our desire to know precisely what caused the problem.
You are not alone :?
John W
aka Bufferstop
Growing old, can't avoid it. Growing up, forget it!
My Layout, My Workbench Blog and My Opinions

User avatar
Peterm
Posts: 1428
Joined: Fri Nov 09, 2007 1:26 pm
Location: Bribie Island. Australia

Re: Class 350 Desiro.

Postby Peterm » Thu Aug 01, 2013 12:44 am

Yep, if it was mine I'd probably try and get a new pcb because I've done all the testing that I'm capable of (I know my limitations). Even then, there's a pcb in every carriage. I do agree that there seems to be two problems... just my luck.

I'm glad I'm not alone though. :)
Pete.

User avatar
Peterm
Posts: 1428
Joined: Fri Nov 09, 2007 1:26 pm
Location: Bribie Island. Australia

Re: Class 350 Desiro.

Postby Peterm » Mon Apr 09, 2018 4:32 am

Well here we are again. Same EMU, new Zimo sound decoder and it still doesn't work properly. I'll be back when I've done some more checking. :x
Pete.

User avatar
Peterm
Posts: 1428
Joined: Fri Nov 09, 2007 1:26 pm
Location: Bribie Island. Australia

Re: Class 350 Desiro.

Postby Peterm » Mon Apr 09, 2018 10:49 pm

The friend that owns this 350 made up a table to show what's happening with the lighting. As I said, it's a new Zimo, an MX644D:
I can't put it on as a word document so I changed to pdf and the site tells me that word and pdf are invalid documents. I'll try to find out what files are valid.
Pete.

GWR_fan
Posts: 4899
Joined: Sun Apr 29, 2012 11:57 pm
Location: Antipodes

Re: Class 350 Desiro.

Postby GWR_fan » Tue Apr 10, 2018 2:13 am

Pete,
five years later and still the same issue, I would ignore the onboard PCB, break the set electrically in the middle and power two cars with the sound decoder and an additional decoder looking after lighting in the other two cars. Replace the overhead lighting with the inexpensive lighting strips common on eBay.

User avatar
RAFHAAA96
Posts: 504
Joined: Tue Feb 19, 2008 1:39 pm
Location: Cyprus

Re: Class 350 Desiro.

Postby RAFHAAA96 » Tue Apr 10, 2018 7:26 am

Peterm wrote:The friend that owns this 350 made up a table to show what's happening with the lighting. As I said, it's a new Zimo, an MX644D:
I can't put it on as a word document so I changed to pdf and the site tells me that word and pdf are invalid documents. I'll try to find out what files are valid.


Take a screen grab of the table and post it as a picture.
Rob
RAF Halton Brat - 96th Entry
http://www.halton96th.co.uk

User avatar
Peterm
Posts: 1428
Joined: Fri Nov 09, 2007 1:26 pm
Location: Bribie Island. Australia

Re: Class 350 Desiro.

Postby Peterm » Tue Apr 10, 2018 10:37 pm

Derr, hadn't thought of that.
Pete.


Return to “DCC Forum”

Who is online

Users browsing this forum: No registered users and 3 guests