Strange problem almost like a short in a loco.

[Nodrog1826]

I have noticed a strange sort of a buzz from one of my locos.

It's sort of a faint buzz you get from a short circuit, but it does not trip the controller, the loco runs ok, everything functions sound, couplers, pantographs and lights, carn't find and short anywhere, but depending upon where it is parked, you get that buzz from one of the bogies, then it shuts down dead, wiggle the bogie from side to side and hey presto it's back to life again.

Any thoughts, just i have been through it and i carn't figure it out, it's probably something obvious and simple i have missed it.

 

[PhilP]

A buzz, sounds like a motor winding, perhaps?

Could also be a spring on a skate, or a busbar in the block vibrating..

See if it feels warm at the top of the skates, or if the motor is getting hot..

PhilP

 

[Nodrog1826]

I was thinking along those lines as well skates or one of the wheel back brushes, but i have traced it to the rear bogie.

 

[Greg Elmassian]

Buzz sounds like a high resistance connection where there should not be.... trace the power path.

Get it buzzing, then get a probe hooked to say the right rail. Now have the probe "move" along the right rail pickup path until the next "juncture" has no buzz.

Greg

 

[ntpntpntp]

Rail joiners sometimes "sing" on DCC if they're a slightly dodgy or high resistance connection, so could be the loco has an iffy wiring joint somewhere as Greg suggests.

 

[Greg Elmassian]

They especially "sing" on DCC! But I think his issue is in his loco, unless he is stopping the loco at the exact same spot each time.

 

[Paul M]

Not a bee in your bonnet then?

 

[Nodrog1826]

It's not a rail joint, its the loco, going to open up the bottom plate and check the pick up shoes and springs then the carbon brushes first then go from there.

 

[Greg Elmassian]

Sounds like the best way, are you going to try to check under power or just visually. I would recommend under power if possible, since it seems you can reproduce the buzzing.

Greg

 

[Nodrog1826]

Going to look for any damage or signs of tracking first, then take off the skates, and plonk it back on the track under power and listen.
Not that that is easy, but my hearing aids do have a volume boost button.

 

[Nodrog1826]

Well took the bottom cover off both bogies checked for signs of damage, the wiring, pickups, skates found nothing of concern, put it back together and hey presto no more buzzing.

Ain't go a clue what it was, but it appears to be all sorted.

 

[Greg Elmassian]

A marginal connection, probably oxidized, contact improved by moving (disassembly and reassembly).

Greg