Early K-Line F-3's W/TMCC Help

[dougdagrump]

While running yesterday my F-3's started acting funky at the dead spots on the switches. They are the earlier ABA models, all powered, with the truck mounted motors. The lead unit would hit the dead spot the head light would go out and the power would drop off until it 's momentum carried it past the dead spot then it would be ok until the next dead spot. Trying to figure out what was happening I stopped it on a long straight put a piece of electrical tape on the center rail and started up the engines. As it crawled forward everything was fine with sounds etc. The minute the first pickup roller hit the tape the engines stopped and the RS stopped after it's normal battery operated time delay.
I pulled the shell thinking maybe a wiring issue but the leads, from both the front and rear truck mounted rollers, are connected at opposite ends of the board. I had assumed that they would be connected to each other prior to attachment to the board.
I am definitely puzzled and looking for help.
Any ideas or suggesstions?
[%-)] [xx(] [|(]

[Roger Bielen]

Try checking the wire connection at the pickup rollers, I have a set of K-line E-3's that I've had to resolder a couple of times. If I remember correctly there is an eyelet on the end of the wire and where the wire goes into the eyelet is where it broke. There has also been discusssions about the springs on the pick-up rollers failing to make good contact.

My standard test is with a continuity meter starting with checking that the circuit from the roller to the board is complete.

[dougdagrump]

Finally made it to RadioShack and picked up a meter. Per Roger's lead I checked continuity from p/u roller to board and it checked good. Rear truck connects to I believe the J6 and the front truck connects to J2. Any other suggesstions ? [X-)]
What about running a jumper from the front P/U lead to the rear P/U lead ? [?]

[Roger Bielen]

Doug, I usually check continuity from the front to the rear p/u's. They should be interconnected. Sorry but I can't offer more than that since I don't know beans about the boards.

[dougdagrump]

Thanks Roger, I just checked continuity from roller to roller and it checks good. Now I am really puzzled, if they are interconnected why would it shut down when the front roller hit the tape in my test while on the track. [%-)] [sigh]

[eZAK]

Doug,

Does this happen in reverse also? Or is it the oposite?

Do you have continuity from the front roller to the center rail when the front roller is over the tape?

My guess is that the rear roller is not making contact with the center rail or very poor contact. Visualy check that the rear roller is in contact with the rail.
If it is then you may have to wire bru***he rollers.

[dougdagrump]

Pat, It acts the same in reverse, moving the rear P/U over the tape, and yes I do have continuity thru the rear P/U with the front on the tape. I'll try taking some of the shine off the roller and use a conductive lube then test again. While I'm at it I might as well do the rollers on the B and trailing A units.

[dougdagrump]

Well got the rollers all cleaned up, took the shine off cleaned 'em then gave them a liberal oiling with conductive lube letting it soak a bit then wiping off the excess. The insides of the rollers must have been pretty filthy the excess lube was really dirty when I wiped them down. Tested them on the track and passed with flying colors. [:D] [:D]
I do believe I will be ordering new rollers in the not to distant future.
Thanks Pat.