N scale BLI decoder upgrade issue

[Lackawannae8]

Recently got my hands on a BLI switcher with a blown decoder. Being me I wasnt going to reinstall junk. So naturally I Had a Nxt18 harness and STX decoder on hand so I stripped out the old BLI junk components, mapped all the lights etc, got it all crammed together and tested out fine but when it runs it will stop randomly then start back up and do that randomly. I cleaned all wheels as well as disassembled every truck cleaned the phos bronze cups and added a dab of noOX inside. Back together and same issue.
Thinking the deco is faulty?
Really hate the thing but its neat if it could just run properly.
I dislike seeing broken engines go to waste.
Looking for any ideas

[peteski]

Very basic test  to check for poor power pickup would be to have the headlight turned on while running the model.  If when the model stalls if the headlight stays on then the power pickup (dirty wheels/track/etx.) is not a problem.  Also make sure all the wiring has solid solder joints and not shorgin to other connections.

Another thing is that since you have Next18 connector in it, just try another decoder with Next18 interface and see how that one behaves.

[Rasputen]

I'm not sure what your DCC setup looks like but I would make sure you don't have another throttle sitting somewhere with the same loco number.  I've seen this happen with Digitrax systems on several occasions.

[peteski]

I'm not sure what your DCC setup looks like but I would make sure you don't have another throttle sitting somewhere with the same loco number.  I've seen this happen with Digitrax systems on several occasions.

True, I stay away from Digitrax and keep forgetting about the multi-throttle "feature".

[Lackawannae8]

Throttle, Dirty track, power feeds etc arent the issue. All connections are soldered and shrink wrapped..

[Lackawannae8]

Very basic test  to check for poor power pickup would be to have the headlight turned on while running the model.  If when the model stalls if the headlight stays on then the power pickup (dirty wheels/track/etx.) is not a problem.  Also make sure all the wiring has solid solder joints and not shorgin to other connections.

Another thing is that since you have Next18 connector in it, just try another decoder with Next18 interface and see how that one behaves.

Also runs fine with DC dummy board.

[John]

Also runs fine with DC dummy board.

Programming?

[Lackawannae8]

Programming?

Funny you mention that. I was thinking about that earlier it does have speed table that I set up thru JMRI.
I may play around with it more tonight. Maybe I need to shorten the speed up even more

[peteski]

Funny you mention that. I was thinking about that earlier it does have speed table that I set up thru JMRI.
I may play around with it more tonight. Maybe I need to shorten the speed up even more

So I assume the headlight stays on while the loco stops?  How exactly do you get it running again, or it just starts up by itself with no input from you?

You didn't specify if the loco stalls while going at constant speed (same speed step) or while you are changing its speed (changing speed steps)?

How about totally disabling the speed tables as a test?  Use CV2, 5, and 6 (if so equipped) or disable all speed modifications. 

[Lackawannae8]

So I assume the headlight stays on while the loco stops?  How exactly do you get it running again, or it just starts up by itself with no input from you?

You didn't specify if the loco stalls while going at constant speed (same speed step) or while you are changing its speed (changing speed steps)?

How about totally disabling the speed tables as a test?  Use CV2, 5, and 6 (if so equipped) or disable all speed modifications.

it basically falls on its face lights out and all. gets back going on its own then does or doesnt do it. super frustrating may as well throw it in the trash and drop in ESU

[Maletrain]

Sounds like a typical very short loss of power to a sound decoder.  Does it happen on straight track with no turnouts?  Could there be something like ballast glue on a rail surface, or something getting hit by the flanges so that it lifts the wheels of the rails?  Running DC would not react the same way.

[peteski]

Yes, if the everything including lights goes out that does seem like a power pickup issue.  BLI decoders used to be very sensitive to this, but everybody was praising Paragon4 as being less touchy. However judging by the photos of Paragon3 and 4, I don't see any additional capacitors added.

If I ever buy another BLI loco (I think I have total of 3), I will only get the Stealth version (thank you BLI!) and install a "real" sound decoder.