We have a "customer" (in quotes because I have never seen him buy any Marklin products here) who seems very adept at killing the decoders in his digital locomotives (about a dozen!). Some of them are factory equipped MFX decoders, some are the older coding switch decoders (8 DIP switches), while still others are either analog locos he had converted to coding switch decoders, or upgraded Delta locos which were also upgraded to coding switch decoders. These conversions and programming (the MFX locos) were apparently done by a "friend of his.

He runs on M track, and is using a 6021 control system. He also has an old "blue" transformer which he says he has used to test the locomotive when he has problems with them (I exploded when I heard this). He says that he runs the locomotives for long periods of time, and some of them stop running after 25 minutes of operation. This seems strange to me, considering that I run the Marklin layout at the store for hours on end with an old Delta system.

So he has been bringing in his "dead" locos for me to fix. Some I test and they run fine. These ones he says will run for a while (anywhere from 5-10 minutes to 30 minutes) and then stop running. Others are very dead. Now because he has the 6021, but doesn't know how to program decoders, and I have the Mobile Station 2, using MFX decoders is out of the question since they all come default address 78. So I used (shudder) ESU LokPilot V4.0.decoders, since I can program the desired addresses for them.

Well, I converted several locos, and the tested fine - here. Sure enough he came back with them, complaining that they stopped working. I tested them, and some worked, some didn't. He said that he would prefer to have me using "genuine" Marklin decoders. I tried to explain the problem about programming them. I also feel that until he addresses the problem with his layout "killing" the decoders that anymore work would be a waste of time.

Anyway, I really don't know what to do about this guy. I wonder if the power source he's using for the 6021 could be the problem. What do you think?

Stuart

If he is using an old blue transformer in analog while "testing" and tries to reverse - there is a great risk of frying the decoder, no matter if it's Märklin or ESU...

The oldest 6080 and the first generation 6090 can mostly take it, but from M 60901 and onwards, including the ESU Märklin era decoders the likelyhood of
blowing it with an old analog blue transformer is greater than the decoder survival odds... Especially the ESU mfx decoders of that time are prone to this
due to very narrow tolerances. I don't expect Märklin's own mfx decoders are any better regarding this...

I've used a 6021 to operate everything from Delta to 6090x, and ESU. Nothing has died, even after leaving some locos running for an hour (giving them a bit of exercise after cleaning and oiling).

Mind you, I use one of the white 32VA transformers to feed the controller.

I might look at his transformer struggling to keep up with the 6021's demands, then overheating and cutting out. That would explain the time delay.

I know if my 6021 has a momentary power interruption (a second or so) it has a bit of a hissy fit - you have to switch off, wait for the red light to stop flashing and then turn the power back on, after which it's perfectly happy. If the overload protection on whatever transformer he's using resets that quickly then it'd probably cause the 6021 to lock up.

See if you can persuade him to try a new transformer, and see if that cures the problem. If you've got one around the shop you might be able to agree something like "if it doesn't work then bring it back and we'll refund you".

this client needs some basic training regarding digital components otherwise you will have a constant recall, some one would have to explain what a blue transformer does when using it with decoders and there are others who think they can install decoders but really have no idea.

I would not recommend using any of the older blue transformers with modern decoders (Zimo/ESU/etc). They can probably still be used with 6090/6080 and earlier.
Many electric companies have tweaked their voltage slightly. The transformers output is a factor of the input so changes can affect the operation. Make sure that the transformer can operate within a range from 110 to 122 VAC. The breaker on the 6-21 is pretty quick to respond. The blue transformers took a little longer to react, but were still pretty good. The older ones simply kept going, but the indicator bulb would dim to show you that there was a problem.

The first thing I would check is the output voltage of the blue transformer. You should also check the output voltage of the 6021 to make sure that it is working normally. I would also make sure that there are not two transformers connected to the same tracks or that the locomotives are not passing over a track which would momentarily connect to two sections with different transformers or analog and digital at the same time.

The second thing that I would check is to make sure that the proper dip switches are activated on the back of the 6021.

I would try to sell the customer a 6647 transformer to upgrade his older one. It is safer both for the trains and for the house.

One last question. When you installed ESU or other modern decoders in older locos, did you also make the necessary changes to the magnet?

Regards

Mike C

The output voltage of some blue transformers is a few volts below that of record-breaking blue transformers. Other consumers (e.g. lights on the layout powered by the same transformer) will also reduce the reversing voltage.
And last but not least the operator will make a difference: If you know that blue transformers you will apply the reversing voltage as short as possible - while others may apply it much longer, waiting in vain for the flash of lights they get from their purely analogue locos.

It's not the colour that makes those transformers dangerous, but IMHO you should not use them without measuring the reversing voltage first.