Legacy berkshire

I think this may be caused by a loose wire or a loose connection to/from a control board. That's what I would look for.

On the locomotive or the track?

You can easily check the track, but I think it is in the engine from what you said.  I would also guess you do not run this much, and therefore the connections could have become oxidized during storage.  I have this same engine.  I do run mine with either my TMCC CAB1 or Legacy CAB2 remote.

A video would be helpful. The buzzing could be a noisy /bad smoke unit fan.

The 3 flashes of the Cab light is the onboard diagnostics saying there's a problem with the fan.

Cycling the power may be getting the  fan to behave.

Good catch Rick.

I'm with Rick, the buzzing is probably the smoke fan, and when it draws too much current, you get the diagnostic blinks and the fan shuts down.

Replacing the fan motor will probably fix this one, the blinks are screaming out the solution!

So should i replace both fan motors at the same time? Or would it just be the main one? Also what is the easiest way to get the blades off of the motor?  and yes correct i dont run it much i think its been a couple or more years i keep it in the original box  in the box just like how they shipped it to me stored away in the closet

Three blinks is the main fan motor.  You simply grab a blade with the needle-nose pliers and pull straight up, they're a friction fit.  When you replace it on the new motor, make sure it's slightly below the level of the bowl but NOT rubbing at the base.  It has to be allowed to run freely.  Also, note the polarity of the old motor and maintain it for the new one, if the fan runs backwards, the smoke volume and velocity will suffer greatly.

Thanks gunner i will be trying that tonight also do u think that will take away the buzzing as well

Does the buzzing stop when the cab light flashes?

Good call when i cycle it and the cab light doesnt flash and the smoke comes out it goes away

Is there a switch anywhere on the engine (bottom, perhaps) to turn smoke off  ?

If so, do you still get the buzzing sound with smoke turned off ?

While you have the smoke unit open, you might want to at least place a small amount of oil on the other fan motor shaft. I place a small external DC power to work the oil into the shaft.  Listen for the improved sound of the motor.

Also, there is a small red gasket on the DSMK units that is easily broke when you pull it apart.  Lionel does sell these as an individual part.  I have to replace them about 50% of the time.  Usually when the smoke unit has been over heated.

Hmmm.  I wondering if the smoke fluid got back into the fan chamber and dried and this is causing the fan blade to rub.  You'll know better when you see it.  I saw this on one repair I did.

@DaveGG posted:

Hmmm.  I wondering if the smoke fluid got back into the fan chamber and dried and this is causing the fan blade to rub.  You'll know better when you see it.  I saw this on one repair I did.

Smoke fluid doesn't typically dry, but it does affect the oilite bearings of the motor.

Agreed.  But for what ever reason, that is what I found in a vision Big Boy smoke unit I repaired.  That had other problems including a heat damaged fan blade.

Yep, when the fan stops, they frequently melt, seen that a number of times.

I might not get to it tonight i have to drag everything back out and hook it up but i will have to try it with the smoke turned off i feel like i should just change them both out cause in the past four days ive had the engine opened three times working on this smoke unit it a big pain in the butt is there a way to check the motors with a digi multi meter cause i hooked them up with a old used 9v and they turn every time

In order to properly test a smoke fan motor, you need to be able to vary both the voltage and monitor the current.  The error is actually triggered by excessive current as a rule.