Single Channel DIMAX Switch Decoder Not Responding

[granddad]

Hi,
I have an 8156501 single channel switch decoder which appears to have failed after only four months (and not all of those in use)
It would occasionally switch the associated point (switch / turnout) in one direction, then refuse to switch in the opposite direction.
Sometimes, operating a different point, and then returning to the suspect point, it would decide to function. But it may not respond at all.

Also, with it directly connected to the 1200Z track output with an attached switch motor as load, it will switch once in both directions, and then refuses to respond unless I disconnect track power for several seconds and then re-apply the power. It will then respond twice, once in either direction, and then "go to sleep" so to speak! Watching the display on the 1200Z, I see a current drain as the switch operates in one direction, but not in the other, and then as I say it will "go to sleep"

I have now tried connecting it, with the attached switch motor, directly to my programming track and I cannot read / write any CVs, not even CV2 the lock CV.
BTW, the switch motor is fine, it works perfectly when connected to a port of another four channel decoder.

Has anyone else experienced this behaviour? If so, how was it rectified?
Methinks it is a dead decoder, it is no more
TIA
Martin
PS: I have also posted this in the Massoth forum

[edit] now this is weird If I leave the decoder for 35+secs with track power still applied, then it will respond again, but only once in either direction! Could it have something to do with CV75 (Time delay for auto return) but that has never been used, and indeed the switch does not "return" however long I leave it. Any ideas anyone?? [/edit]

 

[muns]

Have you tried resetting the switch decoder to factory settings... CV7=55 and CV7=77.

Personally I never liked this version of the Switch Decoder. The programming lock is pants! The new version has a better programming lock!

If you still think it is faulty, contact your supplier.

 

[granddad]

Hi Mark,
Thank you for your reply.
As I said in my OP, I could not "talk" to the decoder at all, so resetting the CVs yesterday was not an option.
However; at some point the decoder has decided to enter into conversation, and so I did just that, i.e. reset to factory defaults, re addressed it and for a short while it behaved. But it soon played up again !
At the moment, today it has been indoors, and has had track power connected to it all of this morning and now it is responding as it should, I can read / write CVs and it switches reliably :
The electronics of the decoder looks as if they are encapsulated in resin, and therefore immune to moisture ingress, so my thinking is that it would not have been damp which effected it, but there is a diatribe in the manual regarding rusting of screws, and placing the decoder in a "protected location" which is difficult when it is directly attached to the point motor. Your thoughts on that aspect would be appreciated Mark.
I am not totally convinced whether it is faulty yet, I will trial it when this windy / wet weather abates.

As an aside; what is the Massoth part number of the "new" version Mark, and how does it differ?

TIA
Martin

 

[muns]

Hi Martin,

The new version has part no 8156601 and uses their new standard enclosure.

http://www.gardenrailoutlet.co.uk/massoth-dimax-single-channel-switch-decoder-ii




The electronics are protected from the elements, the weak spot are the screw terminals.  Cover the terminals and screw heads on both the point motor and switch decoder with petroleum jelly (Vaseline) to prevent oxidisation & corrosion.

 

[granddad]

Mark,
Thank you. I did manage to find mention of the new version on your website / facebook page, and looking at the manual it does appear to be a more weatherproof design (maybe a perceived flaw in the original?) Even with my current decoder, I spray the external electrical connection entries with Servisol Plastic Seal 60, which I use for all of my electronic projects that are likely to encounter moisture. Do we think that the original version does need to be in an enclosure, despite my precautions? Currently it is connected like this:-