N scale Atlas GP-7 Ph 2 (DC) flickering headlights

[carmelmodelrr]

I have a pair of old (about 1996) Atlas GP-7's that ran well until recently.  The headlights began flickering (and the pulling power suffers), so I cleaned the wheels and the wheel wipers, including cleaning the wipers' indentations as well as the contact strips, but there's been no change.  I even lightly lubed the gears and I made certain that the headlight contacts were clean, but that didn't help either. I'm beginning to think that the problem is the motor itself. (Not surprisingly, replacement motors are not available.)  Am I overlooking something--or is it time to place these locos in the dustbin?

Thank you in advance for your responses.

carmelmodelrr

[garethashenden]

If you’re willing to disassemble the locomotive, how does the motor run when connected straight to power? I’m wondering about oxidation on the motor contacts or on the frame that are preventing power from completing the circuit as well as it used to.

If the motor is dead, it’s still better to use the model for parts than to just toss it. Someone will want it.

[carmelmodelrr]

This may be a stupid question but I'll ask it anyway. Would running the loco for a relatively lengthy period of time remove (some of the) oxidation?   

carmel model rr

[mark.hinds]

This may be a stupid question but I'll ask it anyway. Would running the loco for a relatively lengthy period of time remove (some of the) oxidation?   

carmel model rr

It might.  Put it on a test track, and go eat lunch...

[thomasjmdavis]

I have a pair of old (about 1996) Atlas GP-7's that ran well until recently. 
carmelmodelrr

Noting  that this is happening in a PAIR of locomotives -  it strikes me as unlikely that 2 locomotives would suffer the same symptoms at the same time.

1) Are similar symptoms showing up in any other locos? (and are the other locos of the same age?)
2) Have you made any modifications to those 2 locos in the past 30 years?
3) Were they purchased together?
4) You mentioned DC operation.  Have you tried them with another power pack? (I had one year's ago that went a little wacky- flickering lights and so on on some, but not all locomotives. I assume some locos had circuits that handled the power fluctuations better than others.)

[thomasjmdavis]

Also, as garethashenden said, don't throw it out.  I make my non-functioning locos into dummies.  Or, as with their real life counterparts, save the trucks and gears to rebuild others.  And, some shells go on eBay for more than what you paid for a loco new in 1996, especially if it is an odd road name with low production, or a popular roadname (Santa Fe, PRR, etc).  Plus, you can make new friends on Railwire by answering "Oh, I have a couple of those in my junkbox" to a plea for parts in the Trading Post.

[carmelmodelrr]

Actually I run 3(three) of these locos together.  All were purchased at the same time and they’ve always been run together.  The first two (as connected) have the flickering headlights;  the third runs normally.

Carmelmodelrr

[NtheBasement]

Just for insurance I would do a quick check where the boards contact the frame and maybe bend the frame tabs to squeeze the board pads harder.  That's typically the source of flickering lights but doesn't explain the juttering motor.

[carmelmodelrr]

Not sure what boards you are referring to.

Carmelmodelrr

[Lackawannae8]

for shts and giggles how does it react being held to a 9V battery?

[carmelmodelrr]

I think I've solved it.  I disassembled each of the locos, cleaned everything, some with denatured alcohol, then lightly sanded the contact strips before re-inserting them.  I think it was  the brass contact strips that needed cleaning after almost 30 years of use (and storage).

Thank you for your providing ideas and a listening board.

carmelmodelrr

[peteski]

Both symptoms to me clearly indicated intermittent connection somewhere between the track and motor/lights.  Especially since they both exhibit the problem.

I'm glad you resolved the problem, however I would not have sanded the contact surfaces. What grit sandpaper did you use? Sanding creates small scratches which can collect crud faster than a smooth clean surface.  I polish those contact areas, both the strips and the nubs on the trucks to mirror-like finish with a metal polish and a buffing wheel mounted in my Dremel.

[carmelmodelrr]

I used 220 grit sandpaper.  Never thought to use a metal cleaner--will next time.

carmelmodelrr

[peteski]

I used 220 grit sandpaper.  Never thought to use a metal cleaner--will next time.

carmelmodelrr

Ok. If I had to use sandpaper I would have used a finer grit (like 1200 or 600).

[nkalanaga]

Not too late to go back with finer sandpaper and polish out the scratches.