# USA Trains SD 70 MAC main circuit board



## Keoky (Aug 17, 2016)

Hi everyone!
New at the forum. Not quite sure if I post in the correct one. If not, please excuse. Since it is a technical question and I use traditional power, I try this.


I have a little problem with my main circuit board for the USA trains SD 70 MAC. As you can see on the picture, two diodes of the light part burned. The rest of the board is okay. As long as I’m turning of the lights the train works fine. Instead of buying a new circuit board at USA Trains I want to try to fix it myself. My question is: *Does anybody know what specification that diode has?* I could not find the correct color code on the internet. It looks like one blue line!? Maybe somebody can help?


Thanks
Keoky


----------



## Dan Pierce (Jan 2, 2008)

Blue line should be the cathode, verify this with a meter on the good diodes.

Any surface mount diode with a rating of 5 amps or more would work.


----------



## Keoky (Aug 17, 2016)

Thanks!
will test!!!

Keoky


----------



## Robby D (Oct 15, 2009)

I have the boards for $20


----------



## Greg Elmassian (Jan 3, 2008)

Did you figure out what caused the damage, and ensure it won't happen again?

Greg


----------



## Keoky (Aug 17, 2016)

Yes, it was a broken cable. Allready fixed it.


----------



## Keoky (Aug 17, 2016)

@ Robby D
I like fixing stuff  But if everything goes south, I will buy. Do you ship to europe (Austria)? How much is shipping?


----------

