MTH SD90MAC

It has been mentioned here that some Proto 2 engines have defective speakers which deteriorated very fast. Have a Hudson and an Aero Train with this issue, the Aero Train speaker is no longer available though.

If it's an early PS2 with a 5 volt board and 8.4 volt (looks like a 9 Volt) battery, almost certainly the speaker is failing and needs to be replaced.

What is the MTH product number, i.e., xx-xxxx-1?

Hi Barry ,Thank for the reply.The MTH number is 20-2368-1 Premier Union Pacific SD90 MAC. It uses a 8.4 volt white battery.I forgot to say that the bell and horn sounded ok but did have some static.The crew talk is some what clear but also has back ground static.Not sure of the purchase date but I believe it is a early PS-2 model.  RG

If it is a real early one it should not have a charging port.

Barry is giving you good advice on the speaker. Here's a photo of a bad one I replaced, next to the new one. The plating flaked off the old one and messed up the cone. Note that the plating on the old one is sort of yellowish and the new one is bright silvery.

 New speaker on the left, old one on the right.

Thanks for all the great information.The speaker in my SD90 looks just like the one on the

 right of the photo.Looks like cadimum plating.I just ordered a replacement speaker from  MTH and will replace it when it arrives.

Southwest,

Are those wires connected onto screws or are they soldered. I have to replace a speaker myself.

Thanks you, Joe B.

The wires are soldered to the speaker. Not only do the flakes affect the cone, but the magnetism goes out of the magnet when it starts to crumble. Be sure to clean the little pieces out, as the flakes are not good for circuit boards.