I agree. Top pic is of the bottom of the 750. It's covered by a heat sink, then shrink as packaged from the factory.
The picture of the top of the 750, the secodn pic, is interesting. You've got the solder pads. But there appear to be some SMD resistors or diodes soldered on the pads. Was that your work or ???
Mike Lehman
Urbana, IL
I was going to post a couple days ago but the discussion seemed kind of confusing so I deleted the message. Did not think it would apply.
Below is a photo of my 750 with no shrink. The IC, PIC, that is white is against the heat sink. I call it the bottom of the decoder.
The top of the decoder. Rich
The top of the decoder.
Rich
If you ever fall over in public, pick yourself up and say “sorry it’s been a while since I inhabited a body.” And just walk away.
OK, after further analysis, I'm pretty sure the motor circuit blew. Deciding to go ahead and prep to send home to Durango, I started by cutting the Orange wire. Coennectivity OK. Cut the Gray wire. No connectivity. OK, fixed that. Hooking things back up to the motor produced no results. Dedoldered the Orange and Gray motor leads and found no output despite the verified connectivity. Most likely, I pulled the Gray wire loose and it grounded at virtually the same moment to smoke the fuse.
Still mystified by having three big juicy soldering pads for the Red wire. Must be some secret Tsunami mojo.
If you flip the decoder over, on the opposite side from/underneath the wires, you'll find the solder pads. But it's 10 wires versus 6 solder pads. And as I noted, the solder pads don't map to six separate wires, although three of them map to the Red wire...
maxmanIf you are trying to determine if you have power from your pickups to the decoder, can you not just measure across the appropriate points where the pickup wires attach?
That's essentially what I'm trying to do. Put one probe on the termination point in the loco and the other on the decoder where the wire originates. I thought the solder pads would make that easy...
Now, why not turn the decoder over and use the wired points instead of the weird solder pads? Because the M-Tsu is not only shrink-wrapped, but the side in the pic you cited has a heat sink attached to it, which covers the soldered wire ends that you see in the pic.
I'm not quite to the point where I want to tear it apart, in fact if it's got to go to Durango would prefer to not get any more destructive than I've already been. But I'm gonna have to cut it out to do that. At that point I'll cut each wire one at a time, testing for connectivity as I go. If a broken wire does show up, then I'll know it's that.
With my luck, though, it'll be the sixth wire and I'll have five others to fix...which reminds me to cut Orange and Gray first, as they're likely involved. I know Red (Red was the one I broke when futzing with the gearbox and repaired) and Black are good, just can't get to the decoder end of Orange and Gray ones. Obviously, if either was broke, it would display these symptoms. But so would a fried motor control circuit, I guess.
If you go to page 2 of the following link, http://www.soundtraxx.com/dsd/tsunami/Micro-Tsunami%20sell%20sheet.pdf, and zoom in on the picture of the solder connections to the decoder, it appears that every wire lands at a different spot.
If you are trying to determine if you have power from your pickups to the decoder, can you not just measure across the appropriate points where the pickup wires attach? Or am I missing something?
I've had no problem with my Tsunamis other than what I've made for myself. Given most of mine are in Blackstone locos, it doesn't make a whole lot of sense to bother with others. When the budget allows me to get back to diesel installs, I may consider others.
I'm suspecting that I may have blown the motor control fuse, as was mentioned earlier. It's just that no short was every detected and all indications were it was an open circuit, thus my interest in being able to check connectivity on the wiring between the decoder and loco. But all it takes is a slight bump on an exposed wire and the magic smoke comes out. That could have happened, but it sure isn't obvious right now. I just don't want to bother returning the decoder for repair and then find out again it's just a wiring issue. I suppose when I cut it out for return, I can use the cut wires for one last connectivity check, just seemed when I found the pads they would make troubleshooting easier. Guess not.
Many of my steam/NG colleagues are hot for TCS's new WOW, but I'm looking forward to it as a diesel option. LokSound is a possibility there, because I've heard lots of good about them.
I have switched to LokSound Select decoders and have stopped using Tsunamis. The last Tsunami I purchased was for the Atlas NRE Genset. The decoder stopped dead for no apparent reason right after the warranty had expired. Unfortunately, LokSound has not yet come up with a sound file for the Genset, so it is sitting on the dealine until they do.
greg,
Yes, the decoder is that same. I assumed when I found them they would map directly to at least 6 of the 10 wires that come out of the M-Tsu.
What I'm saying is that 3 of the soldering pads display connectivity to the Red wire to the loco (even though there actually is only ONE Red wire that connects to it.) The others are as noted in my previous comment...which doesn't make a whole lot of sense if the solder pads are supposed to be there to hook up your various functions to? Of course, they are covered by the warranty shrink, but I'm long past when that would apply so no harm, no foul in peeling it back to reveal them. I'm just baffled about them...figuring I could use them to check connectivity between the decoder and the various points where the wiring terminated on the loco. No dice.
the decoder in the photo next to the dime isn't the same as your decoder?
Your decoder has only 4 wires that are either red or black?
greg - Philadelphia & Reading / Reading
maxman,
Yes, the pads you see when you peel the shrink back just a bit.
Not really, but it helps illustrate the problem. There's 10 wires coming out, but only 6 solder pads. I figured the pads would represent at least 6 of those wires, but that's not what I found when I went through them, with a majority set-up linked to the Red/+ wire. Maybe they're for additional pick-up wipers or something? I just ran all my wipers together and assigned that as part of a single + input.
mlehmanSo that's not of much use. It's possible that the motor control leads are 5 and 6. But why some many Red leads from the pads?
are these any help?
mlehmanThat's why I was hoping to find some reference to how the 6 solder pads just past the end where the wires enter line up with the 10 wires on the M-Tsu.
What exactly are you describing here? Are these solder pads on the decoder and you had to strip the insulation back to see them?
removed
OK, here's what I found relating to connectivity between tender and loco with the 6 on the Micro-Tsunami solder pads.
Starting from the end with the black wire...
Pad 1 - Red wire
Pad 2 - Black wire
Pad 3 - Red wire
Pad 4 - Red wire
Pad 5 - nothing
Pad 6 - nothing
So that's not of much use. It's possible that the motor control leads are 5 and 6. But why some many Red leads from the pads?
It's in a Sunset HOn3 C-25.
I'm pretty sure it was never shorted in the process here. I'm pretty anal about getting things checked on the programming track when I start messing around under the hood. I found the fault -- another broken lead, fixed it, it came back to life and was trying to run, but I needed to pull the gearbox for an adjustment and when it went back together...nuttin'.
It was my very first Tsu install, so the wiring isn't as organized as I do now. It's hidden well and I really don't want to pull it all just to find a broken wire in one of the six leads up to the loco. That's why I was hoping to find some reference to how the 6 solder pads just past the end where the wires enter line up with the 10 wires on the M-Tsu. I located a couple of them by continuity checking, so will probably continue with that. If I can't verify intact wiring, I'll just wait and call Soundtraxx on Monday.
If it has to go back to Durango, so be it. It would be its second trip home. Thought I killed it on the first install, but they found a broken lead connection out of the decoder, which was fine, fixed it and returned it. That's why I'm thinking the motor circuit is likely not dead. And this thing has acted like an open from the beginning. There was no load on it when it failed.
What kind of locomotive are you working with?
TSU-750's have an internal fuse which will will blow if the motor leads short to the rail leads.
This fuse can only be repaired by the people at SoyndTraxx.
OK, no output at the motor end of the orange and gray leads. Makes sense, motor no turn.
I'm still concerned it's a wire break I can't see. I've tried looking up what the solder pads map to, since there's not enough pads to match up with all the wires, but had no luck finding a useful diagram of them. Since I can't determine any have continuity to either orange or gray leads at the motor end, I'm still wondering if it's just the wire somewhere. I could run new wires, but that will be a PITA I'd rather avoid.
cacole,
The original motor was replaced with a Faulhaber M-1 motor/flywheel, plus a gearbox conversion. So I'm guessing pretty low draw. And it was running fine throughout my diagnosis and correction of a loose connection with no significant load on it. I'm pretty sure the faulty connection did not ground to the frame, which could also result in decoder damage.
Your advice on hooking the VOM to to the orange and grey wires is a good idea though. I was just tracking things down with wiring continuity between decoder and loco to check for any opens.
The M-Tsu has 6 solder pads on it, but there are 10 wires coming out from it. This isn't helping, as I'm not sure exactly which solder pad goes with which wire.
Micro-Tsunami has limited motor current output, and you may have burned it out when trying to run a motor with a heavy current draw.
Did you perform a current draw test on DC power before installing the decoder, and are you sure the motor brushes are totally isolated from any contact with the frame? Burned out motor drive circuitry on the decoder will result in exactly the symptoms you describe.
One test you can try is to disconnect one of the motor wires, connect the decoder's motor output to a VOM, and see if there is any voltage output at all when the throttle is turned up.
I'm troubleshooting a Tsunami install. The red LED on the decoder is lit steady, but has trouble getting past manufacturer's code on programming track with my NCE PowerCab. The sound is there on full power, as well as chuff. But the motor just won't spin. I unsoldered the leads to the motors and gave it DC power and it spins, so it's not dead, either.
My first assumption was a broken wire between the loco and tender. I've been over it mutiple times and don't see a break or loose wire. Whatever it is is an open, though, because no sign of a short when trying it on the program track and sound works fine. I should add the loco is brass and has mutiple wipers, with the tender picking up off both rails.
Any ideas on what I may have missed here? I tried a full reset, but with the wonkiness I'm not sure it took