MTH 30-2159-0 all of a sudden blows horn all of the time

Could the board be damaged if I don’t find/fix what is causing the issue in the first place?  If I remove the speaker or cut the wire that fixes the “hearing” of the horn.

tony

 I don't have those answers for you. I hate seeing posts go unanswered. So I try to draw attention from the experts here.

I don't have any -0 engines. I am not familiar with how they work. I have seen horn blasts from engines that loose ground. I tied the outside rails together and that solved an issue with one engine that kept blasting the horn. Maybe you could try it for a test? If you have a meter for testing, check that all wheels are grounding and check both power pick-up rollers for good paths. Maybe inspect the wires for rubbing on the chassis? Usually right where they connect to the trucks and enter the engine.

 I have also read that horn blasts can be from engines running on AC that has DC leaked to the rails. You may have already eliminated that by trying a different transformer.

 Also check the coupler wires for shorting to the chassis. Again, I am not familiar with these boards. Obviously something is failing or shorting here.

I suspect the horn board has croaked, you should be able to disconnect it.  BTW, there is a volume control on the bottom of the chassis, it's probably partially hidden by the rear truck.

Top circle is the control, bottom arrow/circle is where it shows on the chassis.

John, I will have to look again at this later today.  Your image shows a battery which mine does not have.  There was a hole in the bottom chassis, but there was nothing there, I will check again.  Disconnect the speaker, or the horn board? 

John, here are the pictures of the underside and inside of mine.  Somewhat different than the MTH parts breakout.  It is weird, the owners manual talks about a battery, but there is none.  They talk about the volume control, but there is none.  My guess is they used the same manual for ones with Protosound, 30-2159-1, and the ones that just have the horn, like mine, 30-2159-0.

So do you think I can just cut, or de-solder, the grey wires at the speaker?

Tony

The number you gave brought me to a PS/1 version, you have the DCRU/horn configuration.  The horn board is on top, I believe you can just remove that board, that certainly should silence the horn.

Board removed, no more horn, thanks.  I am guessing the board is not worth fixing and there are no replacement boards.

If you want sound on a conventional locomotive, I have tons of conventional boards that I could fix you up with.  Send me an email and we'll discuss your options.

I have those direct replacements in stock.  It might be the top horn board, but it also could be the bottom DCRU providing a DC offset up to the horn board.  Hard to say without testing.

Either way it can be repaired.

As a note, since you showed it as XX-XXXX-0 it is a conventional type engine, so NO volume switch and also no reset codes.  DCRUs just have a reverse unit lockout switch like almost all conventional engines of any manufacturer.  G