MTH Railking Southern Mohawk with PS2 - What to do?

It is a ps2 5-volt engine with a 8.4-volt battery, you can replace the battery or install a BCR, you can temporarily install A 9-volt battery to try it but do not leave battery installed, just for a test  also before you power it up check the speaker its's a 50mm speaker or smaller with16 ohm check the back of the magnet if there is flaking on the magnet replace the speaker before you can power it up otherwise you risk blowing the audio amplifier!

if you need help repairing it let me know!

Alan

Hi @Alan Mancus and everyone,

So the locomotive FINALLY arrived from the auction house and it looks to be never ran. I opened the tender and the battery does not register on my meter so I am assuming that is dead. I dont know about the speaker, is this the flaking you are talking about? Ive attached some pics.

I am going to Hennings tomorrow for some unrelated things, I'll see if they have a battery and speaker I can purchase.  Really excited to get this running on the track!!

Thanks

Paul

THAT SPEAKER IS TOAST! Install a new one before even thinking about powering up that engine.

ARRGH another STAR speaker Waiting in the shadows to destroy your electronics !

Do NOT power it up until the speaker is changed and the battery

Thanks for the info. I pulled the speaker out to take with me tomorrow and the battery.

I removed the loco shell. How would I know if the board is bad? Anything visual?

If you don't see anything obvious, one thing to do.  Examine this capacitor closely.  If there is any sign of it bulging, lifting off the board, or the top starting to dome out, it needs to be replaced.

Thank you. I checked all of them earlier and saw no signs of leakage of bulging but ill definitely take a closer look again.

I would definitely replace the speaker as it's flaking really bad which means it could blow the audio chip anytime!

Alan

The speaker issue is new to me, how does a flaky magnet affect the audio amplifier?

Is this something common throughout all mth engines or certain models/era?

That is a 16 ohm speaker 50mm round.  Do you use DCS? Either way board in engine so you can power it up without tender attached.  See if it lights up and smoke works.  I would prime smoke unit first.  WIth DCS it will run too.  Just once shut down it will default back to orig ID and you will have to delete engine and readd once you get tender parts fixed.  Need battery for conventional and memory storage in DCS.  G

@Rod M. posted:

The speaker issue is new to me, how does a flaky magnet affect the audio amplifier?

Is this something common throughout all mth engines or certain models/era?

Because, if it's flaking on the outside- think about inside with the voice coil and the tiny gap where the voice coil and it's thin magnet wire with super thin insulation could rub and then short to the metal pole of the magnet assembly. Besides just sounding terrible, it's the tiny warning sign you get before the coil shorts to magnet and because the frame of the speaker may be connected to frame of the tender- AC track power travels up the speaker wires back into the amp blowing it up and maybe taking out the entire board.

More common in PS2, both 5V and PS2 3V systems from my experience. I have piles and piles of bad speakers.

PS3 mainly went to a more modern style and got away from the ceramic magnets- and thus are not subject to this failure. It's really about the ceramic magnet and just being mass produced speakers in that time era.

In a nutshell, the failure is the ceramic or other magnet material the manufacturer chose- they got it wrong, and it self degrades over time. Some had a nickel plated coating to seal in the magnet but when the magnet material fails and expands and changes shape, this just cracks and flakes off the coating- and again, that coating is both outside- but more importantly inside the voice coil area with NO clearance. All it takes is some flake cutting through the insulation on the copper wire coil coil and it's potentially game over.

I'll also add that in this rare case- because not all MTH engines have this type of speaker plastic mounting bracket- is probably why this engine didn't blow up with that bad of a speaker on first power up. I say this because again, this specific plastic speaker bracket, and knowing MTH also used a foam speaker gasket on the front edge of the frame of the speaker- the speaker is electrically floating compared to frame in this photo.

On an engine that used metal tabs- either ones part of the frame stamping or the metal screw and metal bracket- right there is the electrical path of how a voice coil short from failing magnet then also passes AC back up the wires to the board.

A diesel speaker like this with metal tabs holding- that speaker frame is connected to frame, which is connected to wheels, to outer rail.

I ordered a J and W BCR which should arrive in a couple of days to fix the battery issue.

The speaker does have a plastic round housing as well as a plastic ring that sits between the speaker and the tender chassis. I cannot find an exact 16 Ohm 5 W STARR replacement but upon searching this and other forums, I bought a Digikey K 50 WP - 16 OHM speaker, it has a 3W max power but from what I read, that doesnt matter much as long as the tender speaker volume isnt full blast. I also bought the Digikey K 50 FL - 16 OHM but I believe that is of lesser quality than the K 50 WP.

I'm pretty new to this electronics stuff. While I love it, it really makes me appreciate my MCP locos even more.

I do not have a full blown DCS remote and system (wasn't paying $800 on eBay when a new system is coming out soon). I do however have the DCS Remote Commander Control (one track) system which I am hoping works with this engine.

I also have a Base3 on pre-order and maybe it'll arrive before I have grandkids. My son is 7 now

@pault posted:

I cannot find an exact 16 Ohm 5 W STARR replacement but upon searching this and other forums, I bought a Digikey K 50 WP - 16 OHM speaker, it has a 3W max power but from what I read, that doesnt matter much as long as the tender speaker volume isnt full blast. I also bought the Digikey K 50 FL - 16 OHM but I believe that is of lesser quality than the K 50 WP.

Either of those speakers should work fine with your locomotive.

@pault posted:

I do however have the DCS Remote Commander Control (one track) system which I am hoping works with this engine.

Any PS/2 locomotive MUST be factory reset using a full DCS system and not added again to the remote before it'll run with the DCS-RC set.

@pault posted:

I also have a Base3 on pre-order and maybe it'll arrive before I have grandkids. My son is 7 now

I think you're in good company with that wish.

@gunrunnerjohn posted:

Either of those speakers should work fine with your locomotive.

Any PS/2 locomotive MUST be factory reset using a full DCS system and not added again to the remote before it'll run with the DCS-RC set.

I think you're in good company with that wish.

Can I factory reset via conventional method using a Z-500 or so or do I need to find someone with a full DCS system?

@pault posted:

Can I factory reset via conventional method using a Z-500 or so or do I need to find someone with a full DCS system?

No, you MUST use a full DCS system, or at least the DCS Commander (however not the DCS Remote Commander).  Very few people have the DCS Commander, so the full DCS system is probably what you'll need to find.

Well my BCR arrived! Still waiting on the speakers to arrive from Digikey then I have to find a place to be able to DCS factory reset it. I pinged Nicholas Smiths and waiting to hear back from them. They showed up on the MTH service website.

fingers crossed. Cant wait to see this engine come to life.