Failure to start

[Bigmet]

This was a new one on me. Yesterday went to bring a diesel into service after 4 months standing on the layout but not run as it is the last diesel to enter service, (and today we reset to all steam operation in 1955) and it wouldn't go; even though its lights were on so the decoder was definitely on power. Tried 'cancel inertia, CV's 3 and 4' (F4) and away it went at the set speed. Took F4 off while running and it stopped smoothly as expected on the CV4 setting, until at dead slow it stopped with a 'bump': and then wouldn't restart. Put F4 on, started. Eventually determined it wouldn't start or run at all on speed step 1.

Reset the decoder, and normal service was resumed, reliable smooth starts and stops (once all the CV's were reprogammed to the optimum values).

Cause? My guess corruption of the speed step 1 value while parked. Decoder is a 36-554 (Bachmann badged defeatured ESU lokpilot v1) which has been in the Bachmann class 47 since purchase which I think was 2007, never any previous trouble.

[Dad-1]

My only excuse for the failure is some short you may have had while it's been sitting on live tracks.
Having said that the usual result is loss of address, reverting to default 3.
If all else fails reset, which you've proved works, usually first time.

Geoff T.

[Suzie]

These decoders don't like 'pulse stretching', so if you have a command station that allows you to run a DC loco you need to make sure that the DC loco setting is set to stop.

[Bigmet]

Found a second of the Bachmann badged ESU decoders 'lightly deranged' during the 'time travel reset' operation to park every loco not immediately operating correctly positioned ready for the sequence, as we begin with 'all steam' in 1955. This one had CV4 corrupted, stopped dead on speed step 0 command. (I use all the CV4 range on these decoders, they only go to 63 which is just about acceptable for continuously braked trains with diesel traction. But for this limitation I would have purchased many more, as they were a steal when first introduced at £8.99, (a Lenz Silver was then nudging £30, and Zimo's MX63/64 was about £35).

These decoders don't like 'pulse stretching', so if you have a command station that allows you to run a DC loco you need to make sure that the DC loco setting is set to stop.

BINGO! A friend produced an HO US diesel monster A+B twin set in 'Japanese brass' back in February, and at his request I test ran it on the Lenz system temporarily set to DC; as he couldn't run it on his own layout, it needed 3.5A. The very large open frame motors (suspect Pitman or a clone thereof) made a dreadful racket but ran OK and didn't even slightly get warm, plenteous heat sinking.

Susie, thanks for that information. I'll confine any further such DC testing with sole system connection to the isolated test track. That will have to be when I have rebuilt the test track...