I've got two N scale Kato F7s with the drop in digitrax decoders, DN163KOB. They've been working fine for months, until just now. I ran them together a few hours ago, for about ten minutes, then went back to them and now only one responds. I checked the address through the Zephyr's cv readback thing, and the address didn't change. I reset everything with cv 8, and then reprogrammed the address, and still no movement. I took the shell off and attached a lamp to the headlight output (it's the B unit, so I took the LED out), and the bulb lit up, so I know there is power, I can control the bulb through F0 and F4 as well.
Does anyone know why it would work perfectly one moment, and then not drive at all a little while later? There were three engines on the track during this time, and the two others still work fine. There is no hum or gear grinding sounds. The track has power, I ran the other engines through the same spot where the B(roken) unit was, and everything is fine except with the one engine.
Also, there aren't any burn marks on the decoder.
Any ideas?
thanks.
If you reset the decoder, it will be back on default address 3. If you haven't reset the decoder and had it set to a long address, CV 29 may have gotten scrambled. If you have tried to change the address from 3 to a long address, try changing CV 29 to a value of 34 and see if that corrects the problem.
Hmm, I've heard that there are some issues with the space for the motor tabs in some Kato locos, perhaps the motor tabs are not makign contact with the decoder. Obviously the track connections are in contact, or you couldn't program it or control an LED temporarily hooked on. But since it won't move, my guess is the motor contacts. Also, if the motor is accessible enough to turn it, turn the shaft like 1/4 turn and see if it runs - could be a bad motor, too.
--Randy
Modeling the Reading Railroad in the 1950's
Visit my web site at www.readingeastpenn.com for construction updates, DCC Info, and more.
I guess it was the motor tabs, I gently pushed them down a little bit and everything seems fine. Not sure how they became dislodged, nothing was moved between when it worked and when it didn't, but oh well it works now.
Yes, there are problems with the motor tabs making contact with the decoder on this style of board. The E8's, PA's, P42's, and F40PH all share the same design. The F units are the same design although a different size.
I've had some success by carefully shaping the motor contacts. You want to make an arc in each tab with the end that goes under the little grey clip curving up. When the clip is locked in, the curved part of the tab will press down on the decoder. Don't curve the end of the tab down toward the decoder, been there tried that.
If arcing the contact does not work, I've added a little solder to the contact points on my decoders by tinning them. Be careful, only a little is needed. Too much and the grey clip won't go in.
Martin Myers