No sound blue smoke

Sounds like the sound FET failed. Since it's a 5V board you can upgrade to a 3V board with 5V connectors, or look for a cheap engine on the Bay and use it's board. Engines made 2000-2003 and are PS-2 are 5V boards. I have seen a lot of the 5V boards starting to go belly up just from age of the electronics lately, I replace the board with a used one from another engine.

Paul,

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Sounds like the sound FET failed

A minor correction, if you don't mind. That would be the sound amplifier chip. Unfortunate news, regardless.

Paul,Barry thanks for the response. When you mentioned replacing the sound board with a used one do you mean the whole electronic package or just the top board.? It looks like there is one board sandwiched on top of the other. Do the two boards separate easily and I replace just the top board. And did you imply that I can purchase just the 3v sound board and use it with the other board if I change the connectors on the 3v board.

I am afraid I have a SW-9 Switcher of the same MTH Vintage that is starting to have distorted sounds as well.

Thanks

I am afraid I have a SW-9 Switcher of the same MTH Vintage that is starting to have distorted sounds as well.

That's a different story altogether. All you need to do is swap out the speaker for a replacement speaker. They're about $10 from MTH.

Barry,

I will do that.  The other engine that smoked was having the same distortion for a while before it went bad. Can the bad speaker cause the sound board to fry?

 Can the bad speaker cause the sound board to fry?

I've never seen it happen, however, that doesn't mean that it can't.

MY speaker is a 16 ohm 2 watt

BF-0000021

no longer available through MTH

I

MTH has an alternative 16ohm, 5watt speaker.  The key for you is the correct size depending on where your speaker is located.  I believe the BF-31 is a replacement.

The speaker issue with some PS-2 (5V boards) was a deterioration of the magnet/metal coating which fouls the speaker coil.  Causing sound distortion.

The 3V board with 5V connectors will be a direct replacement but it uses the 2.4V battery and a 4 ohm speaker.  Everything else should remain.  G

Thanks everyone for the clarification.

Both engines had the metal flakes in the speakers.

The sw-9 has a 45mm diameter speaker which MTH only has a 4v replacement for that size, so I will have to buy a set of 3volt boards for that engine even though it is working normally. Same for the SD 24 that went up in smoke.

Wow $400 !?

$400 for a new Premier SD 24 and $329 for a new SW-9, I guess it is a better investment

to buy the boards. Any body disagree ?

The sw-9 has a 45mm diameter speaker which MTH only has a 4v replacement for that size, so I will have to buy a set of 3volt boards for that engine even though it is working normally.

Just measure the speaker you have and shop around for 3rd party alternative.

Have you considered waiting (patiently) for MTH to come out with the PS3 upgrade kit?  No battery, better sounds, LED lighting, and more.  As I read your situation, going the PS2 3V route seems like a "repair" rather than an "upgrade".

How about repairing the board?  In this thread if I read it right it appears there's at least one tech at MTH still repairing 5V boards albeit a 13 week turnaround.

I remember a few years back some guys were successful in replacing the audio amp chip on the 5V board.  It is truly a pain to replace that part (and that might not even be your problem) but the point is it can be done and the part itself is only a few bucks. 

Barry,

Pretty obvious now why none are available from MTH. Thoroughly searched the internet for a 16 ohm 2 watt or better  speaker that is 45mm in diameter. No body that I can find makes one that size in 16 ohm. Plenty available at 2 inches however. Unfortunately the case holding the speaker under the SW-9 engine has a maximum width of 1.75 " (45mm) available for a speaker. Unless you have a resource I am back to the 3v board swap.

Stan2004,

I dont know much about the PS3 upgrade nor what it will cost. Do you?

Yes it would be a repair instead of an upgrade but I am happy with the operation of the two engines as designed. I guess I should have asked the question " how has the reliability and success rate of the 3v board with 5v connectors been to justify not just buying new engines (with PS3 ?).

Thanks for your response.

I will check the shop today, MTH said they don't have the BF-31?  I certainly would not drop $200 plus because of a bad speaker.  G

GGG

Thanks, this is what I got off the MTH Parts site for speaker replacement.

Measuring my speaker and its case. the biggest that can fit is BF-000021

BF-0000031

Star NR-045-A1Z04 16 2 45 mm Dia X 17mm 2002 RK F-3 w/PS2 (John Deere)

Only 2002 & 2003 models      No longeravailable

BF-0000021

Star FR-045-A1421 16 5 45mm Dia x 22mm GN R-2 Steam, SW-9, SW-1500 w/PS2

Only SW-9 & SW-1500 built in 2002      no longer available

No specifics other than what I read here.  I was just commenting on your “investment” question.  What struck me was a comment that MTH will release a final batch of PS2 3V upgrade kits this year then future ones would be PS3. So if history repeats itself, if something goes south with your repaired PS2 3V boards in a few years, will you be forced to upgrade to PS3 anyway?

I understand wanting to get your SD sounds running again right away, but an option for your SW is to install a 45mm 8-ohm speaker which presumably you can find(?), and add an 8-ohm resistor (50 cents) so it appears to the electronics as 16-ohms.  The loudness will drop but the scratchiness goes away – this keeps you in business while waiting (patiently) for the PS3 upgrade situation to play out. If the PS3 SW is already available, perhaps a 45mm PS3-compatible speaker is already available unless they re-tooled the frame.

Yes thats possible but that resitor can get very hot. I am not sure what the typical output of this amp is in the engine. I could put an 8.2 ohm 2 watt in series. Ill have to test it and see how hot it gets. The last thing I need is more smoke in my train room.

Skylar  don't you have another engine from wich you can borrow the speaker for a test? at least you will know if it's a speaker problem or iof your audio chip is dead.

PIDJY.

I have 8 PS2 engines all but these 2 are 3volt PS2. In any case I dont want to really take good ones apart. Both speakers in these 5v board engines have metal shavings collected on the magnets on the paper side of the speaker. I know for sure the SD-24 has lost its chip. I just wonder if the speaker problem caused it and I am going to eventually lose the sw-9 chip if I dont replace the speaker.
If anyone has a 45mm 16 ohm speaker they  would like to sell I would be grateful to buy it.

Replacing that amplifier chip is some mighty fine handi-work!

Since that 16 ohm speaker does not seem forthcoming, I think an 8 ohm of the correct size with a 2-3 Watt 8 ohm resistor in series is a practical option - especially if (?) the PS3 chassis for that engine uses the same tooling for that sized speaker.  With rare-earth magnet coils now readily available, the volume output loss may not be that bad.

If there's room, you could put two 8 ohm speakers in series, makes for more sound.   Obviously, they should be similar wattage ratings.

Stan 2004,

Yes I think you are correct. I have found an acceptable sized speaker 8 ohms with a 2 watt output. I checked the data  sheet for the amp chip and it is 5 watt max.

So I am going to try a 8 ohm 2 watt resistor in series and see how it goes.

By the way I consider it a miracle that I unsolderd and resoldered the amp chip without wrecking the board!

Thankyou for your input.

It's good you got it out.  I have a tip for the next one.

Don't be concerned about breaking the leads, AAMOF, break/cut all of them before applying any heat.  Then you can remove them one at a time, much easier than trying to remove them all at once.

John,

Thanks I will keep that it mind for the next one, although with my fat fingers and the smallest dykes I had to cut with, I couldnt get at but the end leads until I got it partially separated from the board.

Just flex it back and forth until the leads break they won't last long, even with a small amount of travel.

Royboy,

Brilliant ! Where were you when I was using language my mother would be washing my mouth out for !

I think this post may help a lot of us maybe who are afraid to tackle this kind of project.

Gee, I have one of those as well.  I confess that I haven't tried to use it for PCB repair.

Skylar what about changing the TDA7056A - (3w 8ohms) for a TDA7056B (5w 16ohms) could me much more easier to find a 48mm 5W 16ohms speaker than a 3w 8ohms.

@gunrunnerjohn. I will not try to do anything on my locs with that stuff !!!