# LGB 2080S analog sound issues



## Chata86 (Dec 5, 2010)

I like to bring out this train for Christmas, but it has been a long while. I forget how long the sound hasn't been working well, but I'm anxious to get the sound working well again. I bought the train back in the mid 80s.

First issue, when the train is below about 70% power, the chuff puff sound dies. That tells me that the 9v isn't getting used correctly, since it handles low speed sounds.
Second issue is that the horn never sounds when pushing the bottom button pushed.
Third issue was that the bell never dinged when the other bottom button is pushed.

I have an electronics background. I also fix old pinball machines for fun. I'd prefer to keep the analog system, over replacing it all.

I checked the wires, and contacts, everything looks good.

I disassembled the LGB analog electronic control box. First thing I'm noticing is that the large NPN transistor in there on the edge is running very hot. I noticed several variable resistors and capacitors in here. These parts often oxidize overtime, so I turned them around and back where they were. This restored the bell ring!

I also know that overtime capacitors can fail. It'd probably be worth replacing them and the hot transistor.

Anyone have any suggestions on repairing this train's sounds? Does anyone specialize in repairing or restored electronic boards?


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## Cougar Rock Rail (Jan 2, 2008)

Does anyone specialize in repairing or restored electronic boards? 

Your best bet is to call Klaus at Massoth--he has more experience than anyone with LGB boards and will most likely be able to help you. 

Phone +1 (770) 886-6670 

Keith


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## Chata86 (Dec 5, 2010)

I had an electrical engineer friend at work look at the train. 

He explained that silicon (like transistors, diodes, and regulators) rarely fail, but capacitors have a lifetime that varies depending on the heat they're exposed to. Personally, I've seen some fail in under 5 years, but obviously many last much longer. 

Indeed, one of the capacitors was revealed to be shorted when measured with a multimeter. That capacitor short is why the regulator chip was so hot. Once we replaced the shorted capacitor, I heard the LGB's analog horn for the first time in over a decade! Still needs a little tuning though.


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## handycam (Jan 23, 2010)

Hello. I've very limited "electrical" expertise. Just yesterday I disassembled my 2080S (early version, with screw in lamps) to investigate why the bell wasn't working. After finding all wires/connections intact (except for the loco's outlet plug in rear), I reassembled. Did you take photos of your disassembled unit? Did you find the variable resistors inside the electronic "black box" with the pot., or was it on the inverted circuit board above the loco's motor block? Please advise. Also, although the smoke unit still works, I tried to trace it back to a board. I could not find it. Do you know if this early unit has a 5V or 18V smoke unit? I'd sure like to get this up to snuff. Thanks!


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## handycam (Jan 23, 2010)

Whoops, forgot to mention. The 2080S schematic available through LGB.de is NOT similar to my unit.


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## Dan Pierce (Jan 2, 2008)

Look at the color of the smoke unit wires. Black.white is 5 volt, brown/yellow is 18 volt. 

White/white is 24 volt. 

If the bulbs screw in they are 18 volts and if plug in with leads with flat tops they are 5 volt.


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