Mth WIU and TIU connevity issue

How is the TIU powered?

Fundamental problem. The WIU comes with a limited 5V supply. The USB out can attempt to power the TIU logic- however this is generally not good. I sounds like you are in this "brownout" state where your TIU is NOT yet getting power into aux or fixed 1 channel and this load of the 5V WIU power supply may be sagging trying to power both- hence not fully booting.

With a WIU and TIU, I always recommend aux power into the TIU so it self powers and is not drawing down 5V USB power.

Ah that makes a whole lotta sense!! Thank you Vernon!!

Hi Vernon, what should I use to power the TIU? Mine did not come with a power supply.

@chefmarkt69 posted:

Hi Vernon, what should I use to power the TIU? Mine did not come with a power supply.

None of them do- a 12 to 22V AC or DC supply ideally about 1.5 to 2A rating.

MTH made a part number but it does not have to be this supply MTH 50-240 Z-DC24 24-Watt Power Supply

If just using the TIU- 12V is fine and the lowest source I would use, however when using the TIU with an AIU- the AIU is getting and using a 12V source from the TIU- so input to the TIU needs to be greater than 12V for proper headroom to provided that output voltage to the AIU. Again, better here is that 14-22V input range.

No trying to make this confusing, just trying to be complete. My own layout, I do not use AIU normally, so 12V DC 2A aux power input works great. I discovered however when testing AIU functionality (just to learn more about the AIU and it's technical details), a higher voltage input was required or else the AIU did not work for me.

Reach into the surplus pile of wall power adapters many folks have left over from old wireless routers- many are 12V with at least 1A or greater and have the correct coaxial power jack.

Perfect thank you and have a good night!!

Hello Vernon,

update , I found a power cord and plugged it into the TIU. But the WIU is still not connecting to the TIU. I have to cycle the power on the WIU 3-4 times before it will connect.

@chefmarkt69 posted:

Hello Vernon,

update , I found a power cord and plugged it into the TIU. But the WIU is still not connecting to the TIU. I have to cycle the power on the WIU 3-4 times before it will connect.

Well, that is NOT good and I would stop doing that (multiple reboots). You are at risk for corrupting the WIFI module and since they are no longer readily available replacements- this could get ugly and costly. This is a tiny operating system that boots from flash memory, and then the actual WIU application runs on top of that. Short cycling the boot by removing power can and has caused corruption in the module so bad I have seen where you cannot even boot into LUCI interface to re-flash the firmware.

@chefmarkt69 posted:

lately when I power up my TIU and my WIU the white light on the WIU blinks and blinks. It doesn’t connect with my TIU v6.1. So I unplug the WIU a few times and then it will connect with my TIU. It just started doing this lately.

One common failure is the power jack connector (mini USB) on the WIU mainboard. There is a super thin trace when ripped or cracked making it intermittent that is one possible explanation. It does this because the module needs multiple voltages, so 5V goes in, but that trace has 3 paths and one is a lower volt regulator (likely 3.3V). I'm saying this because I recently was working on one with a loose jack, bypassed the jack, and the system still would not fully boot. The module was getting power- just not all the different voltages- and sure enough, the jack damage was more than just the jack trace ripped, it spread and more was damaged.

https://ogrforum.com/...t-wiu-power-jack-fix

Again, bottom line, this is one of those modules I power constantly and do not turn on and off with the layout. It boots once and stays operational. I also feel in some ways- a repaired WIU with alternate power jack system replacing the mini USB with something like a JST-PH 2 pin jack pair is much less likely to fail when properly used with strain relief techniques and thus improves long term reliability.

Again, one known failure mode- the power jack rips and/or cracks the trace and eventually rips right off the PCB. If you catch it BEFORE major damage, it's way, way, way better.

Hi Vernon,

wow that is a lot of information. I do understand and my technical skills are not that great. How would I have this looked at and repaired if needed?

I had a wiu do something similar last year where it wouldn't connect to any tiu even after doing a factory reset. Last ditch effort of reloading the firmware  on the wiu seemed to solve the problem.

Agreed- re-flashing the firmware in LUCI is a good possible next thing to try.

So maybe I could reload the firmware. Might be more at my skill level. Is there a place I can find instructions on how to do this? Thank you

@chefmarkt69 posted:

So maybe I could reload the firmware. Might be more at my skill level. Is there a place I can find instructions on how to do this? Thank you

The manual https://mthtrains.com/sites/de...ction/50as13515i.pdf

The firmware location https://mthtrains.com/dcs-software-downloads

Page 9 LUCI interface

Also a video https://www.youtube.com/watch?v=2Xy6oQwjuaI

you guys are

awesome!!!!! Thank you

The MTH WiFi unit power jack is notorious for ripping off the board.  I've fixed at least a dozen of these.  The root problem was that the manufacturing was poor and they didn't properly secure the jack to the PCB.  That being the case, it was easy to flex the USB cord and break the jack loose from the board.

Here are some "before" pictures, note the unsoldered tabs on both sides of the jack!

Here are some "after" pictures, note all thetabs on both sides of the jack are soldered!

Sadly, I usually get them after the jack is already ripped off.  If that's the case, I use a new jack and solder and epoxy it in place to give it maximum strength.

Hi Gunrunner, I do get power to the WIU no problem it is the connection to the Tiu that it doesn’t connect both of them together. So would this be it affecting the signal connection. One member said to re flash the software because it get maybe corrupted?

@chefmarkt69 posted:

Hi Gunrunner, I do get power to the WIU no problem it is the connection to the Tiu that it doesn’t connect both of them together. So would this be it affecting the signal connection. One member said to re flash the software because it get maybe corrupted?

Let me see if I can try to help. It's important that we understand status indicators here.

manual link again https://mthtrains.com/sites/de...ction/50as13515i.pdf

@chefmarkt69 posted:

lately when I power up my TIU and my WIU the white light on the WIU blinks and blinks. The white light is the WPS indicator- and yes it blinks as an output of the module based on what the firmware is doing at the time. It does not provide good indication (since we don't have source code) for actual status of the application or module. So yes, it indicates there is some power to the module- doesn't mean it is booted and working as intended.

The green PWR LED is only indicating if 5V is present. Again due to the tiny traces and potential ripping of the trace from a loose power jack there are scenarios where the green PWR led might be lit, and you might even get a white WPS blinking- but the module still is not booting fully or at all into the application we know as WIU function.

It doesn’t connect with my TIU v6.1. So I unplug the WIU a few times and then it will connect with my TIU. Again, a lot of problems with this simple yet not simple sentence. The normal boot at first power up is green PWR, then blue LAN flashes once, then white WPS blinks, then eventually blue WIFI LED lights- and that indicates it's now standing up the wifi network. All of this WITHOUT a TIU plugged in.

Then, once I KNOW I have booted, the wifi is stood up and the blue WIFI LED is solid- then connecting a TIU to the USB port - THEN after a second I get the purple TIU LED lit, now it's operational.

It just started doing this lately.- Again, the white blinking WPS light and it never going out is a clue to the problem, the module is not getting past that part of the firmware code.

Again, clearly, yes, there are a couple of things that could have happened recently. It could be the trace is cracked and intermittent and so the module sometimes boots but not 100%. I actually have seen first hand such a failure where the module had power- just not all the different voltages because of a tiny crack in that main power trace.

It could be just short cycling power during booting at some point corrupted the flash and so it boots sometimes and other times it gets hung up.

The point I'm trying to make is from experience- try your best not to "short cycle" power to the WIU. The less boot cycles the better. It's possible to corrupt one of these to the point it is very hard if not near impossible to fix via normal methods. By normal methods, I mean accessing the LUCI interface. If it won't boot to that- if you cannot get a wifi network stood up- how on earth can you flash the firmware? Again, I've seen these bricked and have a few bricked modules in my parts box- waiting for the spare time to attempt to flash them over serial interfaces not normally exposed in the tiny wifi module as installed in the WIU.

Hi Vernon,

I understand your points fully. Today I came home and turned the power to my layout and the WIU booted up no problem at all. Who knows computers and tech is a fun and interesting road at times. I will check all that you have given me to look at. I do appreciate all of your help and sorry if I am frustrating you. My lack of knowledge of some of this tech is limited. But you have taught me more than I knew yesterday. Thank you

Vernon and the rest of the support team,

I ended up reflashing the firmware in my WIU. It was so simple and it was quick. That did the trick I am back up and running again!! So funny I think when I can’t run my trains I go though train withdraws!!!! Thank you all so much for the help and support you are all awesome!!!!!!! Have a good weekend!!