PS-3 Sudden UNK short

Is that the PS32 board?  You could take a stab at replacing that component, but I have no idea what caused the issue.  ANY short to ground with any pin on the PS/3 boards is bad news.

GRJ, As for the model#, all's I know, it's a 50-1912 Upgrade Kit directly from MTH over a year ago. I'd gladly try to swap out the component, if I knew exactly what it is? I haven,t pulled the PS3 board out of a spare loco yet, as the cooked component (Mosfet?) is to bad to read any markings. Then after I look at the good board, maybe I'll be able to search on Digi-Key? Thanks for your thoughts GRJ!!!

OK, that's the diesel upgrade kit.  The board is actually almost identical to the PS32 board, they based off the same design.  I'd probably try to find a dead board and salvage that component from it and see if you could revive it.  Note that it's a fairly fine pitch SMT part, so if your soldering skills aren't up to it, you might want to send it somewhere to make the attempt.

GRJ, thanks as always! Strange course of events. I switched out the PS3 for another PS3 Upgrade and, the results are GREAT! I wouldn't be surprised if my first PS3 wasn't defected from the git go! The second board performs like it should! The first one took 17 volts to maintain a constant speed, whereas the second board needs 12 volts for the same performance!!! Which is more consistent with my other engines. I might give MTH Service a shot, in the event they may agree with a my thoughts? The part number on the case of the good component, is "189L" , I'll have to see if I can cross that with any results?

I have several dead PS/3 boards, I could extract that component from one if you have the ability to solder it on.  I don't know that would fix it as it may have been something else that caused that failure.

GRJ, My gut is to take you up on the part. Thank you!  That component (5 legs/pads) I've had decent success with. The IC's with many pads, well, my success rating is low for replacing the removed part (removal isn't so bad). At this point, I have nothing to lose, and everything to gain! Merry Christmas!

Send me an email to my profile address with your shipping address.

Buy the component new and try replacing.  May work but may not.  Also those pad are very easily damaged and lifted.  You may have crushed a wire unintentionally.  G

Thank you GRJ!!!

Thanks G!!!

@GGG posted:

Buy the component new and try replacing.  May work but may not.  Also those pad are very easily damaged and lifted.  You may have crushed a wire unintentionally.  G

If we knew what component it was, buying would be an option.  I don't see a label on it, and finding it on the ASC PS/3 parts replacement list I'm not having any luck either.

Yes you do, look at the ASC parts diagram again.  It is U-277.  :-)  G

Odd, I wasn't matching the part to the location on the board, maybe I need my vision checked.

It seems nobody has those in stock...

Given that the part number is available, I certainly agree, start with a new part, greater chance of success.

I checked and I don't have any of those in my parts.

Update: With the help of GRJ, I ordered and received the blown part! Removed it, causing harm to a trace, made the necessary repair, soldered in the new part, and bingo, the PS3 is up and running like new! No one is more surprised than me, as I thought for sure,it would have needed more than one component. Thanks Guys!!!