Legacy GP-9 Issues

Actually, first stop is to reseat all the boards and connectors.  I seriously doubt this is old enough to have capacitors going bad.

If it's a component failure, top suspect is the R4LC for the older Legacy GP9 models, I've had to replace one of those.

I reseated everything multiple times to no avail. I'm sure it's the driver board, a few components were heating up each time after it quit receiving commands. I was already planning on getting a replacement board, but posted this in hopes it might have an easy fix. No problem. 

Well, the motor driver board is a frequent source of issues, but usually stuff like smoke unit and not accepting commands would be the R4LC.

I agree with gunrunner,check all connector's to the r4lc,tap and twist board(carefully,you don't want to create a problem). Before you throw out the baby with the bath water,check under magnification all solder joints. You stated that out of the box it acted normaly. Does that mean you had all functions? Going forward, backwards, sitting still,acts up cold, hot,how much time?

This is the specific parts page for the engine. https://www.lionelsupport.com/...43-a6bb-3eaf17fda6a9

I'm ignorant to these electronics, but from what I can see, it appears that the R4LC isn't used on here. Pictured here are the only boards in this other than the RS board, and I highlighted the areas where it was heating up. 

Keith,

I recently had this problem on a earlier Legacy E8.  The engine would run fine in the foam cradle, but would only run briefly once on the track.  Also the front coupler was constantly triggering.  I found that several of the screws on the truck halves had worked loose, causing the castings to sag, and create an intermittent ground.  Pop the trucks and give them a look.  Good luck!

Bruce

Now, if you had posted the actual product number of the GP9, we would have known it has the RCMC, and would have had a different diagnosis.

gunrunnerjohn posted:

If it's a component failure, top suspect is the R4LC for the older Legacy GP9 models, I've had to replace one of those.

The above quote should have clued you in that I didn't know what model you were talking about!  I have several Legacy GP9 models, however mine are the earlier modular electronics.

You most likely have either a bad motor that's pulling too much current and causing the overheating or a bad RCMC.

In the future, the product number is always a useful thing to start such a conversation with, it saves us all chasing phantoms.

Right john and isn't that yellow cap twisted? Shorted Leg's?

Ron464nyc posted:

Right john and isn't that yellow cap twisted? Shorted Leg's?

Looks odd, doesn't it.  Since that is obviously the Lionel parts page picture, who knows what condition the board that they shot was in.

Update: Took everything apart, put it back together, tightened screws, etc. It works! (Less than it did) 

The weird thing is that it takes one command, starts up without sound, then does nothing but have on lights and smoke. But in conventional, sounds are there but won't move. Oh well. I'll order a new board...

John, I was going to give a product number, then thought to myself "I'm sure they're all the same"  Oops. Sorry for the miscommunication. 

Thank you all for the help

New horn button

One common fault is failure of those smoke fets.  You can disconnect smoke, and test.  IF a FET is visually damaged, remove and test.  G

Removing and replacing parts on the RCMC isn't for the novice.