Problems with Black 5 TTS decoders in older Black 5 models

[LuLuJo]

I have been trying to fit the recent Black 5 TTS decoder into some older Hornby Black 5 locos. However I have accounted a repeated problem. The first one worked ok for a while which encouraged me to buy some more. I have now tried 3 sperate decoders in 3 different models. All have been DCC fitted before with either hattons or Laisdcc decoders and ran well.

What happens is the sound works ok. But when you tell the loco to start it hisses and starts to move then the sound shuits down and it stops. It then tries to restart with the hiss and then stops. Or it will not start at all.  I am pretty sure the decoder cannot supply enough power to the loco and its protection circuit is shutting down. Swapping the decoder for a none sound one and they work fine again. I stripped one of the locos down and found there was some resistance in the back axle which was sorted with some oil. It worked ok for a bit but now works no longer. 

So my conclusion is the decoders are probably okay for brand new Black 5 models but not suitable for the older types  with the dcc socket in the loco. Its very disappointing and has wasted a lot of time. Has anyone else encountered this problem or better still solved it?

[Phil_Spiegel.]

I too have  experienced similar behaviour with newly installed TTS decoders in 'older' models. ( by older, here I  mean the generation with 2 sprung contacts between tender and loco,  but the effect can be with other makes/ models too...  Yes, I too ( briefly ) checked correct operation with their existing decoders before conversion, , and àlso verified TTS decoder operation using an ESU decoder tester because ( with the exception of the streamlined Duchess of Hamilton,) I have been fitting decoder and speaker in the tender ( with  5mm acoustic foam due to arrive today to cover the speaker/ coal space before topping with some real coal   )

Most of these have been stored unused for years ( recent priority to H0 and G portable layouts ) .. As indicated by many of them having had 'Macoder' Lenz1000 decoders from when I converted them from  Zero-1 circa 2002-3 ( I also discovered 2 mazak wrotted and crumbling Class 31s 8-(  ... I hope new castings can be bought as a spare part from Margate as it is a known problem and compatible  models are still in production )

Obviously I rechecked continuity of track pickups through to decoder and on to motor.

Lifting the loco slightly seemed to help overcome this starting eviction, as also did changing CV 2 (starting voltage) followed by more running in*†* - where I am fitting the decoders I only have about 0.5m of track to go back and forth on ... A continuous loop and half an hour would probably sort it all .

(*** using a released original batch Hornby decoder I have now digitised my Stephenson's Roçket ( decoder under tender ) .... Given good contact it runs well, but is stiff and needs running in ... I may add pickups on the tender in preference to permanently coupled coaches.) An overweight driver añd fireman would help too 8-)

It poses 2 questions: does the increased length of thin wire to and from the rear mounted decoder cause a momentary voltage drop? And does the decoder run any form of automatic pi adjustment when finding a new scenario ??? (Some makes do )

Another 'problem' experienced with one of my S15 decoders ... After full function testing on the ESU tester was an apparent inability to reprogram !!  Despite the motor kicks occurring, it would not respond to the new address and some times not the old or a reset ... Not good after cutting leads to fit ( to an N class)... Tried again yesterday..  As usual I am using a Roco Multimaus (cabled) and amplifier ... No read back ...but I have also used an MCP which gives read back ...not always successfully hence I prefer the simple and faster  no read back method.   Back on the ESU tester ....' Dead' decoder finally accepted a reset and all worked again....

The Solution appeared to be WAITING longer after programming with no power present  ( check your 'STOP' mode or lift off track monenrarilly ). ,.THIS decoder seem to need a longer period wi5 no power after reprogramming to make it start up correctly with the new address.  ... Finally managed to set it to 3861 ready to re install....with all functions working.  I have not noticed this longer requiredctime interval before

And finally: All those old Macoders ( motor and1 non directional light made especially for UK )... Will be appearing inside coaches and guards vans to give controlled light ing - replacing always-on lighting.

[96RAF]

What you have deduced about self protection seems correct, so I would fit a blanking plate and do a motor stall current test to determine if you arekeeping within TTS decoder limits per the spec sheet.

 

If you need to know how to do the test there are links in the forums to Brian Lamberts site which details the method.