BLI M1 sound problem

[C62-2]

I have an n scale BLI M1 (Paragon 2) that is not making any chuff sounds while running. All of the other sounds seem to be ok. I tried resetting the decoder by setting cv8 to 8, but this didn't solve the problem. Does anyone have any suggestions?

Thanks,

Doug

[C62-2]

The problem got solved, thanks to some email help from BLI. The chuff sensor was bad, and setting CV 246 = 192 bypassed the sensor.

[peteski]

So this loco uses a chuff sensor/cam?  IIRC this is the 1st N scale steam loco with factory-installed sound decoder to use a cam for triggering chuffs.  I had no idea. 

[C62-2]

I haven't had a chance to take a look inside yet (I had assumed the original problem was a CV programming issue, not a hardware thing), but there is a reed switch to detect the rotation of the flywheel, which has a magnet. I have a replacement for the reed switch, and will post pictures when I get enough time off from work stuff to open it up and perform surgery on it.

[peteski]

I haven't had a chance to take a look inside yet (I had assumed the original problem was a CV programming issue, not a hardware thing), but there is a reed switch to detect the rotation of the flywheel, which has a magnet. I have a replacement for the reed switch, and will post pictures when I get enough time off from work stuff to open it up and perform surgery on it.

If you have a multimeter (ohm-meter or continuity tester) then it would make sense to check the reed switch in the loco before replacing it.   The contacts should close and open as the magnet moves by.  Unless you can see physical damage, blindly swapping parts is not a good solution.

If you don't have a multimeter, then it might be a good idea to get one. This hobby (especially DCC) involves a need for electrical troubleshooting where a multimeter is a diagnostic tool.

[k27463]

I've had the pleasure of dealing with BLI's reed switches in HO equipment -- they fail fairly regularly.

I'd almost just expect it at this point.

[peteski]

I've had the pleasure of dealing with BLI's reed switches in HO equipment -- they fail fairly regularly.

I'd almost just expect it at this point.

I have plenty of experience with reed switches in general, and unless physically damaged (broken glass envelope), they are very reliable, especially in very low-current environment like a chuff trigger sensor.  But I have zero experience with those specific reed switches and the way they are installed, your advice trumps mine.