MTH 20-2543-1 Pioneer Zephyr RUNS,but no sounds!!!!!!SOUND PROBLEMS!!!

Right speaker gone bad.

Chuck Sartor posted:

Right speaker gone bad.

If that is the problem,I"ll be very happy. Anyone know what Ohm speaker is supposed to go in this engine?

That is the right speaker for the engine, it is to be a 16 ohm.

Gene Anstine

Ok.Tried a working 16 ohm speaker, still no sound.

Getting a remote(finally found a used one!!!) later this week, and was told to try to do a factory reset,and see how electronics act as far as add MTH engine etc... goes.

How can I check if the volume pot is working correctly or not?

I have repaired lots of old Lionel trains, but I am a complete novice at trying to troubleshoot an MTH electronic train.

As stated earlier,the train runs magnificent ,smokes ,but there just are no sounds what so  ever.

Any other suggestions on what to check??

This train has been ran in conventional mode only so far,on an old Lionel trainsformer with no whistle or bell buttons.

Once I get the remote,I'll be able to know a lot more,but like I said earlier,there are no physical signs of the board being fried or any meltdown.No bad smells,no signs of magic smoke.

Any suggestions or advice greatly appreciated.Thanks,Kenny Baughman

Sweep the volume control from end to end several times to clean the internal wiper.

The amplifier may be bad. Forum member GGG may possibly be able to repair/replace if no other options work.

HI Kenny love your videos ! Nick

rockstars1989 posted:

HI Kenny love your videos ! Nick

Thanks Nick,I haven't been too serious about making videos over the past 6 months,but I'm about to get down and do some more INTERESTING things.I can barely afford to be in this hobby,but I LOVE IT so much,that I FIND ways to enjoy my O gauge trains. 

I'm going to start putting some more effort into doing videos again,as I am off the road,and running truck local for the winter at least,so that should give me some time to get somekind of new setup going,because I'm getting too old to be on the floor playing with trains!!!!!!

It won't be anything spectacular,as I am saving that for when I purchase my own home here in the not too distant future.But all of this is good practice ,I've learned a heck of a lot over the past year,as I had never picked up an MTH train before in my life.

I have been trying to learn how to fix them,but there is no Greenburg with exploded diagrams for MTH stuff that I know of.This Zephyr is way cool,I bought to resell,but I have fallen in love with it instead.I Vill get sose zounds going!!!!One vay or zan nother!!!!!!!

Thanks.Do you have a You Tube Channel???

Get rid of that speaker. Once the plating starts to flake off, it can get into your boards and ruin them. Here is a good replacement for it. 

https://www.parts-express.com/...a3a7qyg57010fx60005c

If still no sound, the boards may already be damaged. You also need a rechargeable 8.4v battery or a BCR in its place...

Tom

kennyb posted:

 

I Vill get sose zounds going!!!!One vay or zan nother!!!!!!!

 

After you go thru the various reset/re-load exercises, if you believe the problem is with the audio amplifier electronics...

The extremely-difficult-to-change audio-amplifier IC is the TDA7056 (see attached datasheet).  The TDA7056 is obsolete but you can find it on eBay for maybe $2-3.  Did I say that this IC is extremely-difficult-to-change?

If you are an experienced electronics troubleshooter but just aren't familiar with the MTH PS2 electronics repair, the datasheet should take you to the next diagnostic step.  That is, as you change the volume control pot in conventional, you can see if the volume control input pin on the IC changes.  When you get the remote, then when you change volume in command-mode on the handheld you should likewise see that volume control pin on the IC change.  The TDA7056 is a BTL amplifier so by looking at the output pins you can tell if, perhaps, the amplifier outputs are stuck or "wiggling" (even using just a voltmeter...vs. an oscilloscope).  Likewise, when firing the horn/whistle you out to be able to measure some activity at the amplifier input pin. 

If all this is gobbledygook, contact member GGG who I'd say has the most experience restoring audio on these boards.

stan2004 posted:

kennyb posted:

 

I Vill get sose zounds going!!!!One vay or zan nother!!!!!!!

 

After you go thru the various reset/re-load exercises, if you believe the problem is with the audio amplifier electronics...

The extremely-difficult-to-change audio-amplifier IC is the TDA7056 (see attached datasheet).  The TDA7056 is obsolete but you can find it on eBay for maybe $2-3.  Did I say that this IC is extremely-difficult-to-change?

If you are an experienced electronics troubleshooter but just aren't familiar with the MTH PS2 electronics repair, the datasheet should take you to the next diagnostic step.  That is, as you change the volume control pot in conventional, you can see if the volume control input pin on the IC changes.  When you get the remote, then when you change volume in command-mode on the handheld you should likewise see that volume control pin on the IC change.  The TDA7056 is a BTL amplifier so by looking at the output pins you can tell if, perhaps, the amplifier outputs are stuck or "wiggling" (even using just a voltmeter...vs. an oscilloscope).  Likewise, when firing the horn/whistle you out to be able to measure some activity at the amplifier input pin. 

If all this is gobbledygook, contact member GGG who I'd say has the most experience restoring audio on these boards.

Thank You so much for this information,this is the kind of stuff I need to learn!!!!!

Do you have access to anymore info like this???I also need an exploded parts diagram of the MTH Zephyr,

I think the one I have is 20-2543-1,or 20--2250-1,it really doesn't matter I believe for the few little body add ons I need,as MTH has been known to make great use out of the same mold,and why not?

I do not see an exploded parts diagram on the MTH website for this engine,but maybe I'm too new at navigating the website,it might be on there.

Thank you once again for the detailed information.

EVen if I don't understand it today,I will study it,and LEARN how to do these replacements by trial and error,that;s how I learned to fix postwar and prewar,things got easier as time went along.

I have a passion inside me to learn how to fix these,and with determination and a lot of help from great people,I know it can be  learned.-Kenny B

I have a few of those TDA7056 amplifier chips in stock.  If I want to change them, I first cut all the legs off the old one right at the plastic package, then pull the legs out one at a time from the PCB heating with the soldering iron.  Clean up the holes and you can install the new chip.  If you try to remove the old chip in one piece, it's MUCH harder as Stan suggests.