yeah i ordered a new bridge rectifier that sits in the cab, not the controller, but another forum member notified me that this bridge is for the magnet. I had completely removed the rectifier and the buzz was still there. That part should be here any day now and I will go ahead and try it anyways, but i'm thinking that's not the issue now. There was also some discussion by Dale about some small diodes seen in the controller board with labels D3 and D4 (the D3 label is hiding under a capacitor but you can see the triangle next to it) They are stamped S1 B on top of them. All these little parts are like $0.30 to $0.60 each so i'm kind of thinking of ordering a bunch of capacitors, diodes and polyfuses and see where it takes me. I'm just struggling with finding the comparable replacement with a few of these items.
The caps on the board are dirt common Panasonic SMT caps, I use them on my Super-Chuffer, lighting board, and the upcoming sound board. Digikey has the exact replacements.
If you do order new caps, first try just touching the terminals of the new ones against the old ones, making sure the polarity matches up of course. This will effectively double the capacitance. See if the hum is reduced. Everytime you touch a soldering iron to the pads you risk lifting the foil so only change the parts out if you are fairly certain its bad.
Pete
Norton posted:Everytime you touch a soldering iron to the pads you risk lifting the foil so only change the parts out if you are fairly certain its bad.
That's especially true if you don't have a temperature controlled soldering station to minimize the heat.
SMD caps you mean? I found them on digikey but there are like 50 different versions that all have the 47uf and 16V rating for the larger one. Some have different ripple current ratings and impedance ratings. Then on the smaller one i see its a 35V but it doesn't show a uF rating. There are several different 35V aluminum capacitors with various uF ratings
Obviously, you have to know the voltage, capacity, and size of the cap to find a replacement. If they don't have the capacity on the cap, which I think is pretty rare, then you have a bit of a problem. 
The ripple and impedance ratings are not a major issue in this application I would expect.
Ok so I got my parts today. First I replaced the capacitors on the motors and that did nothing. Second I replaced the small diode located at d3, the one that previously gave a reading in both directions when powered up. I turned the power on and it still buzzed but that diode no longer read in both directions. However after replacing that diode diode d4 started reading in both directions. It didn't do this before. So I went ahead and replaced diode d4. When I powered up the buzz was gone for about 3 seconds and then it came back. Now when ever I power up it takes second or so before the buzzing starts. After replacing that diode then diode d3 started reading in 2 directions again. I went ahead and replaced the smaller 35a aluminum cap capacitor and it didn't remove the buzz. However now it reads about 13 volts dc where before it was like 28. I accidentally ordered the wrong capacitor for the other cap so I haven't replaced that one. I'm wondering if after installing the new diodes it worked momentarily and then burned them out cause something else is bad? Now the crane doesn't work either....
so I messed around more with the d3 diode and got the crane to work again but the voltage on the capacitor went back up to 28 volts again. At this point is it more advantageous to order a whole new board ($71 shipped from Lionel) or send the whole thing in to Lionel to repair? I only paid $120 for the entire crane so it hurts to spend this much on it.
Something is clearly taking out the diodes.
So in your opinion is it worth paying labor to have someone troubleshoot it or just buy a whole new board? I just worry after troubleshooting it someone else will just say I need a new board. I also have a slight concern that something in the crane is contributing to the issue although I doubt it at this point.
Well, it's hard to say. I hesitate to recommend either course of action. If I say new board and there's something in the crane that is killing the boards... OOPS! OTOH, if I recommend someone look at the new board and that doesn't work out... OOPS!
See what I mean. 
I guess the sure bet would be to send the whole thing in to be looked at. Is it best just to send it directly to lionel or does anyone have a recommended repairman that would be capable and maybe save some money?
I don't know that Lionel will work on it if it's more than three years old. Isn't that their newly stated repair policy?
I wouldn't know? I'm afraid there's probably not many people that would troubleshoot the circuit board vs just ordering a new one. I'm open to suggestions on where to look. I sent an email to Brasseurs to see if they would do something like that. I haven't heard back yet. I also sent an email to a local repairman close by and am waiting to hear back. How about you John, is this up your alley so to speak?
Well, my plate is pretty full right now, so I'll pass. Whoever looks at it, I'd suggest they have the whole unit. You first want to insure that problems other than the circuit board are addressed before putting in a new circuit board. For the prices involved, I'd put in a new circuit board. If you find a Lionel dealer, you might be able to get it a bit cheaper and save shipping since it would be coming with other orders.
