Had an ops session this afternoon and my dt400R throttle suddenly showed "hyroglyphics" and some numbers (where the cv sound function numbers show up) then went blank/dead.
My other throttle (a dt402R) throttle remains working just fine. I tried the 400 plugged in with and without a battery. Does it need to go back to the factory or are there fixes I can try?
Earlier today I reset the command station with opSwitch 36 to purge loco addresses, but that hasn't affected the other throttle or anything else.
Thanks if anyone can help a.s.a.p. I only saw one other thread about this and that was resolved by a replacement after several trips to the factory. Is that always necessary?
Jim
Raised on the Erie Lackawanna Mainline- Supt. of the Black River Transfer & Terminal R.R.
Sometimes the 'burp it like a baby' technique works, if the main processors needs to be reseated - personally I'd rather just open the thing up and press the chip into the socket the right way.
However, the symptoms you have are often more likely a blown capacitor. There was a period of time when many manufacturers of elecronic equipment were getting counterfeit garbage components from China - not by choice. And these less than third rate capacitors usually did not meet the specificationd and failed after relatively short lives. If that's what's happened, there's not much choice other than to have it take a vacation to Florida. It's not really hard to repalce through-hole capacitors, but the problem is there is no schematic avaialble from Digitrax that would tell you what value capacitors are needed, and I wouldn't trust what's printed on the failed one - if it's even still readable.
You could try a OpSw 39 reset which is the 'real' reset - also means you need to reset any other OpSw settings that were changed from the default. But since the DT402 works fine, it's most likely not a command station problem.
Everyone's had the capacitor problem, most famously computer motherboards have died rather spectacular deaths especially if overclocked, and since the caps in question are usually part of the power regulation circuitry, it takes the CPU and maybe other components along with it. A blown cap is usually fairly obvious when looking at it, if it hasn't actively spewed internal bits, it will be bulged. The leaked electrolyte is harmful to circuit board traces, so there can be a lot more damage than just a failed capacitor.
--Randy
Modeling the Reading Railroad in the 1950's
Visit my web site at www.readingeastpenn.com for construction updates, DCC Info, and more.
Thanks Randy. Do you or anyone else here have experience opening the throttle case? Any "tricks" involved besides screws so as not to break anything? I'd like to visually verify the capacitor possiblility. The throttle is several years old and out of warranty but didn't know if digitrax might charge more if I opened it myself anyway. Thanks as always, Jim
Capt. Grimek anyone else here have experience opening the throttle case?
There are some operators that like to place a mini-toggle on the battery lead to keep batteries from draining. I don't feel it is a worthwhile modification but here's a link that has instructions for opening the throttle::
http://mvns.railfan.net/vsthrottle.htm
click the photos to enlarge them a bit.
Digitrax doesn't mind if the throttle has been opened, they have a flat-rate repair service ($25. for throttles) and they have always been fair anytime I've needed service.
http://www.digitrax.com/support/returns/step1/
Good Luck, Ed
Jim,I've had a lot of experience opening DT400 cases. I have installed a couple dozen SPST toggles into throttles for my fellow club members. Some are tricky and others are easy. You just never know.
Start by opening the battery door and removing the two screws. Then slide the back of the throttle upwards. It should slide up at least 1/4" or better. Next, you want to try lifting the rear of the case away from the front. Try pushing against the inside of the battery compartment of the front while pulling up on the rear of the case. If it won't even budge, try sliding the case halves even further. Those J-hooks are rather long.I like to pull on one side at a time, and I've occasionally used a flat screwdriver as a mini pry bar to help (but be careful or you could mar the edge of the plastic case). Usually, with a little patience, I can open one case side like a zipper, then the other side will pop free.
To put it back together, simply line it up and snap it home. You may have to gently squeeze one of the battery terminals to get it to fit past the circuit board. CAUTION: take special care to mind the battery wires when snapping the case closed. The case can shear these tiny wires like the best wire cutters without you even noticing. Trust me. I know. Just make sure the wires are tucked up and away from any shearing action by the case components.
Randy,As for the toggle being worthwhile, it is when you consider that the battery doors cost $5 each to replace. The door "fingers" always seem to break with use. Also, it prevents absentminded folks who like to store their battery in their throttle from flipping it over backwards against the spring vs. simply reversing the polarity like they should be doing. The battery gets real hot when you do that. BTW, the weblink you posted shows a couple odd things. For one, the wire he's using is huge. I just use decoder wire, which is the same stuff that's in the throttle already. Secondly, to locate the toggle, place the top piece back in and then scribe the gap between the cord, the component and the board into the back of the top piece. Then find the center and drill the right sized hole. I also give myself a little more space by cutting off about half the "nut" of the ziptie. Lastly, I leave the top piece out until after I reassemble the case. It will snap right in after the fact, and prevents a lot of fumbling around trying to get it to stay still when one is snapping the case halves back together.
Lastly, about Digitrax. I love their products and their repair service, don't get me wrong, but they did something odd with one of my fellow club member's throttles. It was sent in for a repair of a throttle knob, and it had one of my SPST toggles installed in it. The repair tech at Digitrax was apparently confused by my simple wiring. Instead of leaving it be or removing it entirely, the tech piggybacked new wiring on top of mine. The result was that when the toggle was "off", the battery was connected. When the toggle was "on", it shorted out the battery. Not too swift, IMHO. The member didn't notice until he switched his throttle "off" and put it in his pocket. Minutes later, he got one hot pocket.
Paul A. Cutler III
I didn't say anything about the switch, that was Ed. I don't have any wireless throttles, yet. My last two layouts were small enough that I could get to anywhere with just 2 or 3 UP5s so I never upgraded either throttle to wireless. Dunno if I'd put a switch in mine or not - there hasn't been much issue with the battery door or putting the battery in shorting (vs rolling it over) even with many of the people not having ANY DCC at home. Most people just take the battery out when done using a throttle (we use rechargeables) and though it's been a while, I think there was only 1 broken battery door out of a dozen throttles. If I was goign to make electrical modifications to the DT40x series, I'd change it over to use AA batteries and a boost converter to get better battery life. I need to poke around and see just what is in there that needs 9V, most everything should be 5V or 3.3V, so it all the battery does is feed into a linear regulator, no wonder the battery life is so bad. I could also replace that with a low drop out regulator so it would keep workign well below 8 volts, too.
Wow. Thanks very much Paul for the succinct explanation regarding opening the throttle case. Ed thanks for the reassurance that it'll be ok with Digitrax (esp. as it's out of warrantee anyway). I'll give it a good smack upside the head today and if that doesn't reseat the board, I'll take a look see. I may wait until I'm with an electronically illuminated friend (which usually is not me!) to see if he can spot anything else that may be visually apparent.
Thanks as always for the great responses and help,
Oopsie, my bad. Yeah, that was Ed. I was scrolling up and down and in a rush.