P2k GP7 with QSI acting up, need help.

Model Railroader General Discussion (Model Railroader)
1

For some reason my GP7 has been acting up lately, it will no longer move, sound will work and strangly when i turn up the throttle the engire revs (but only in forward). I reset the decoder and still no luck [:(] (for refernce im using a digitrax zephyer) can anyone offer any help?

2

You may have a gear that is no longer rotating with its shaft. If you feel comfortable, and it is no longer in warranty, pop the cover of the loco and run it to see if the gears all move.

Otherwise, you must have a faulty decoder…it works on the sound circuit, but won’t instruct the motor…that will be borne out if the motor does not turn, which you can verify if you wipe a small streak of paint, nail polish, or use a magic marker in a spiral line around a visible portion of the motor shaft.

Edit- not the shaft, the flywheel…sorry.

3

Try double-clicking F6. THis sounds like disconnect mode (page 21 of the QSI DCC manual I have, but I don’t think I ever downloaded the very newest one). In disconnect all the functions will work (horn, bell) and the motor will rev when the throttle is advanced but the loco will not move. Normally this is entered by pressing F9, which is a bit tough with a Zephyr since it only goes to F8 (unless you have another throttle like a DT400 or UT4 plugged in). Failing the F6 to restart it, try using the wand and doing a full reset. If you hear the sound effect of the diesel engine but not the whirring of the actual drive motor, there’s probably no mechanical problem at all.

–Randy

4

It worked!!! [:D] I double tapped F6 and it was back to normal, the speed was a little too high (probally due to the reset, ill adjust that later) , Thank you Randy [:)]

5

Well done, Randy. I hadn’t even thought of the first disconnect since I don’t use it? I’ll have to remember that people can inadvertently place QSI’s in that state, or do it and forget.

6

I only know because I tried it, once. Don;t use it at all. I suppose it could be useful on the early Amtrak HEP units where the prime mover was in run 8 all the time to provide HEP, even when standing still in a station. Oh, and I did once read the entire 300 some pages of the QSI manual, but I’m wierd like that.

–Randy