Massoth 'XLS' Decoder shutdown

[beavercreek]

here is my suggestions for Tim's friend and for Cliff. Change CV49 to 0 instead of 2, and check if that corrects the problem. If it does, reset CV49 to 2 and set CV 63 to to 128. I have encountered this problem before and I explored various solutions and this solution seem to work and make sense based upon what I saw was happening with the current draw dispayed by the navigator.

Mohammed

Just edited as Cliff asked at the same time!
Hi Mohammed
I have just checked the CVs in the Massoth XLS manual and cv 49 is set to 3 (not 2) at factory and CV 63 does not seem to exist???? I am probably missing something as I am certainly not the greastest knowledge in DCC!

 

[Cliff George]

Cliff, am I correct in assuming that the power buffer that you use is a capacitor based one. Is it the Massoth produced one or your own design?

Mike, I use the Massoth one, the high capacity goldcap one where I have room for it. Really a power buffer is only needed, in my opinion, on short wheelbase locos with few pickups, but these are exactly the locos that you will struggle to find room for a powerbuffer. Another way is to feed in power from following trucks. Although power pick up wheel sets can seem expensive they are not a expensive as a power buffer.

I did think about doing my own since I work in electronics but I didn't find the time.

PM me if I can help anyway.

 

[mbendebba]

hello Cliff:
you should try setting CV49 to 0 nonetheless (no bemf digital or analog, parallel only). Sorry about the 63 (typo), it should have been 62 (adjustment strength).
Mohammed

 

[Tim Brien]

Thankyou all for your advice.
Mike,
sorry no way to run on a Massoth system.

Mark,
I will contact Garry and get the decoder details. He will be running the loco today with the body removed to aid in cooling of the board to see if this helps.

Mohammed,
many thanks, will try these settings.

 

[Tim Brien]

Mark,
Garry contacted me. the only sticker on the board is the Massoth number for a Mallet installation, indicating that it has Mallet sounds loaded.
The underside of the board just has circuit board details printed directly on the board, 1014712 and 011531.
Garry indicated that the board smelled burnt. Maximum current draw even loaded with carriages has never exceeded 1.2 amps. He is going to run today with the body removed and see if it shuts down.
I noticed a posting from July, 2010 on the Massoth forum where an XLS had been running fine for sometime and then developed a problem whereby it would travel a few feet then shutdown and keep repeating this. No one responded to his posting.

 

[muns]

Hi Tim,

Thanks. I have seen Gary's posts on the Massoth forum and it would seem that when running without the loco body it does not shut down. So it would seem that the decoder is overheating!

 

[Tim Brien]

Mark,
when one compares the software update versions on the Massoth site, it seems that a version 2.1 could conceivably be several years old. This decoder was sold as new stock by the dealer (distributor) only about three months ago. The replacement Mogul decoder (was a warranty replacement for a version 2.5, received less than two months ago) was a version 2.2 and this could be up to two years old.

The shutdown issue may not be current with the latest version decoders and may be limited to these apparently older decoders. If I was buying them then I would expect and demand the latest manufactured product, not an older version that had been updated to current specifications.
Also, as regards Garry's decoder installation, they were mounted to a metal base using the two standoff factory mounts on the circuit board. This ensures air circulation around the decoder. Very odd that the decoder would have a burnt smell considering the extremely low current draw.

 

[beavercreek]

I am probably showing my ignorance as the world of DCC is a realatively new thing to me..but...could the board be tested with direct feed from the track and then to power another separate motor block and speaker just in case it was something to do with the lcoo wiring/function etc?

 

[Tim Brien]

If you read the history then both (two decoders are at fault, both XLS) decoders ran almost perfectly for several weeks. The owner recalls that several times the Mallet decoder shutdown momentarily but did not give it much thought, thinking that dirty track may have been the issue.

Both decoders have exactly the same issue, one mounted in a LGB Mallet and one in a LGB Mogul. When first advised I asked the owner to ensure the Mallet pickups were clean and that his track was clean. He cleaned the backs of the wheels and used his LGB track cleaner to spotlessly clean his track. The mogul then started to play up exactly one week later. With both decoders having the same symptoms then it seems the fault lay in the decoders themselves.

His 'technical expert' (????) advised him that his problem is because firstly, he is not using a Massoth DCC system and secondly, he is powering his system using a switchmode DC power supply. The expert told him to use AC power to power his system. This seems like a load of crock. The NCE is NMRA compliant, as is the Massoth decoder. Also the expert told him that he knows how to correct the issue but requires him to ship it several hundred miles to him to carry out the rectification. The only fix is a replacement current release decoder in each case. The decoders were only purchased new several months ago and yet could be several years old each.

 

[beavercreek]

Yes I did read about the clean track and wheels earlier, I was just trying to take one possible variable out of the equation. But the fact that it has happened to two locos makes this very interesting.. But I would still test the boards away from the two locos...just in case........
It is strange that there has not been a flood of problems concerning the older version of the boards (that have been updated to version 2.6). If Gary's two are performing like this and if the decoders were from bad batches, there would be many people with the problem.
There have been two guys on the forum posting about their problems (Cliff and jimmielx), one with exactly the same symptoms.
Perhaps there is some DC, or other pulse through the track, leaking from the NCE system intermittently causing the board to become 'confused' and maybe heat up?
Perhaps there is an intermittant voltage drop inside the locos circuitry from the wheels/pickups that causes the board to to keep restting or to heat up.
Is there anyone near to Gary that can test the loco with a Massoth system or other power supply/command station on a different layout, rather than the one that he is using?
If it is only the two decoders that are at fault, maybe it is an unfortunate coincidence that they are heating up too much.
As you have said, Massoth have noted an issue with the LS board so maybe there are some bad XLS jobbies out there and Gary is unlucky to have found two of them that were made at different times.
Perhaps the software update is a little buggy and affects the older boards.

Diagnosing and fixing electronics with ICEs is like trying to tame a load of snakes.............:

 

[ntpntpntp]

His 'technical expert' (????) advised him that his problem is because firstly, he is not using a Massoth DCC system and secondly, he is powering his system using a switchmode DC power supply. The expert told him to use AC power to power his system. This seems like a load of crock.

Must admit that's not the first time I've heard/read of recommendation NOT to use switching-mode DC supplies with DCC gear, but I have no recollection where I read it and why it might be a bad idea.

Certainly should be able to run Massoth decoders with NCE gear, so that is spurious info. I have an XL or 2 running on my NCE 10 amp system with no problems, but no XLS sound decoders as yet.

 

[mbendebba]

Tim: if Gary thinks that his problem is heat build-up, the simplest solution would be to drill a few holes in the floor of the cab of the loco to allow the heat to escape, and he would be done with it.
I think it is extremely unfortunate that some dealers would sell as new a decoder that has been sitting on the shelf for quite some time since decoders, like most other electronics products, tend to be upgraded frequently.
However, it is conceivable that xls decoder hardware has not change much since Gary's decoders were manufactured, just software changes.

 

[Tim Brien]

The reason for using a switchmode DC power supply is that Garry lives in the country and the AC supply is not totally reliable in that voltages may vary up to 10%. This would then affect the input to the central station. Even with me in a major city, power fluctuations are not unknown. Power drops and spikes do occur.

In so far as using a Massoth system, well only the well heeled seem to purchase them. A 12 amp sytem out here will cost around $2500 - $3000 including power supply. Add to this several decoders and one is outlaying around $5000 to go digital. An NCE system may be had for around $750 for a wireless 10 amp set up.

Mohammed,
if heat dissipation is the fix and holes are required, then why is this not the standard for all XLS installations. Garry mounted the decoder using the stock raised mounts, so that cooling air is able to travel around the board. He has done several installations prior the Massoth boards, but these have all been NCE 4 amp and 8 amp boards, with no problems. Strange that the two Massoth boards are the ones causing the problems.
The fix is new current manufacture boards, not old stock.

 

[mbendebba]

Tim:
I never suggested that heat dissipation is the fix, Garry is the one who seems to think so. I believe the problem can be fixed by tweaking the Back EMF CVs a little.
I agree with you on the matter of new old stock, the dealer shouldn't have done that. Decoders with ver 2.1 are clearly new old stock and as a customer I would accept them as new either.

 

[Cliff George]

...could the board be tested with direct feed from the track and then to power another separate motor block and speaker just in case it was something to do with the lcoo wiring/function etc?

Yes that is a step I'd take with any problem installs I had. ESU even make a piece of equipment to make this easy to do (not that it is hard anyway).

http://www.dragon-gscale.co.uk/esu-51900-decoder-tester-2859-p.asp
Actually I'm not sure this tester would be much good in our scale, given that the motors and speakers we use are probably different, but it gives an idea of what can be done. I'd set something up myself with the same motor and speaker the engine was using.

I've not taken my own advice and tested my own problem decoders in this way yet!

Mike, your DCC Knowledge is very good.

 

[Tim Brien]

Just a follow-up. Garry has turned off digital load control (CV49=0) and found that the locomotive moved off at speed step '12'. Previously with load control on it moved off at speed step 2. He turned off the load control on the Mogul as well and it also moved off at speed step 12. Mid-speed was set at '50' (factory setting), giving a very flat driving curve with most power allocated to the upper half of the curve.

I advised him to adjust the speed curve to a proportional linear 'curve', giving analogue like power progression. The Mogul loco now moves off at speed step '4' which was normal for this loco.

When the weather improves he will run both locomotives and test.

 

[mbendebba]

Tim:
by moved off at speed step 12 do you mean it did not start moving from a complete stop until the remote dial was turned to speed step 12.?

 

[ntpntpntp]

The reason for using a switchmode DC power supply is that Garry lives in the country and the AC supply is not totally reliable in that voltages may vary up to 10%. This would then affect the input to the central station. Even with me in a major city, power fluctuations are not unknown. Power drops and spikes do occur.

10% fluctuation at mains voltage, by the time that fluctuation is transformed down to the 18V ish for the NCE gear, is only a couple of volts and shouldn't be significant at all. Drops and spikes might be a concern though.

Anyway, damned if I can find any current evidence of where I read warnings aginst using switched-mode supplies. Let's discount that for now and concentrate on the decoders and firmware/heat issues I guess.

 

[Tim Brien]

Mohammed,
correct. Mallet loco required speed step '12' on cab to commence moving. With load control on the loco would move off at position '2'.

Mogul with load control off also would not move off until speed step '12'. After adjusting drive curve to straight 'linear' line, loco moved off at '4' which is normal for this loco.

 

[mbendebba]

Tim: The change is both cases is toally expected and should not be of concern at the moment. now what I am hoping to hear is that the locomotive is no longer shutting down even at full throttle.