MTH HO SD70m-2 CV and motor issues PLEASE HELPPP

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julienjj

Noodle is good
Weird, who the heck was the idiot to make a DCC ready unit that is not even DCC ready, just DCC socket installed?
Mth:rolleyes:

hehe:D

Strange cause mine worked righ out of the box with a 8 pin plug. I just had to read the manual to know wich side was the pin 1 because they havent printed it on the board
 

guilford681

New Member
YIKES! I was going to get some MTH dcc ready versions to install Tsunami's like Josh mentioned but diburning just saved my arse! I was thinking about ordering some undec Athearn M-2s but when I heard my friends ACe I changed my mind. There is something about factory decoders from any manufacturer. It is probably due to crappy speakers. I guess I'll have to go with dcc ready Athearns and wait till JULY!

Tim
 

diburning

AlcoHaulic
Well, the club electrician knew it was a disaster as soon as he opened it. It's not all that hard to find where pin 1 is as per DCC standard, it's the orange wire, but of course, MTH uses a weird color coding system.

The Athearn model comes with a tsunami. I think sealing the speaker with a bit of caulk or silicone would be a lot easier than rewiring an MTH. I'm not trying to open up a can of worms, but I'd rather get the Athearn due to it being more accurate; the ditch lights are appropriately sized, and theres a dynamic brake grid instead of the fan that MTH put in there.
 

hamltnblue

Active Member
CJcrescent, MTH doesn't follow the NMRA guidelines for DCC.
They have a method to set CV29 to 38 which sets the loco to it's cab number.
Go figure.
 

RailFanRick

GTW Lives!
Call address 55 then set CV 55 to 55, in other words use 55 three times in the whole process, that should work. :)
 

bigB

Active Member
Im confused, are you guys talking about the PS3 MTH SD70ACe or the DCC ready version?

I have a DCC ready version of the MTH SD70ACe that ran fine for about an hour and then it got jerky, not very fast at top speed and just now it just burned up a NCE decoder. I have another NCE decoder but forgot which address it was addressed to and cant get it to respond. I tried the "loco 00" ops mode cv 8 to 8 to cv 30 to 2 and the loco 55 to cv 55 to 55 thing. No dice. All the lights work but something is screwy. No shorts on my layout.
 

diburning

AlcoHaulic
You have to reset it according to NCE's reset procedure (CV 30 to 2). CV 55 to 55 is for ProtoSound 3 only. If the decoder resets with no problem, then you're good. If the reset procedure doesn't work, your decoder is toasted.

There is a fellow club member at the club I belong to that has two of the MTH SD70ACes that are DCC ready. The club electrician installed the decoders for him. At first with the decoder plugged in, the locos caused a short. So, the club electrician ripped all the electronics out, and rewired the whole thing. He had to isolate the ditch lights from the headlight and flip the polarity (MTH uses a negative common instead of a positive common like the rest of the world). It worked for a while, but then it toasted the decoder.

So, the club electrician replaced the decoder, and the DCC system saw it as a short. As soon as he put the loco on the tracks, the decoder toasted. When he used a multimeter to check for shorts and high power draw, he found that the surface mount LEDs were operating at 200 milliamps (or so he told me) and said that the surface mount LEDs in the loco must not be standard (why am I not surprised?)

(The club electrician said that it was a nightmare and that if he owned the loco, it would be embedded in the wall by now)
 

bigB

Active Member
Eric,

Yes, one NCE SRJ decoder is definitely fried, and I see know other reason for it but the MTH DCC ready loco doing it. Ive had zero issues on my layout with any of my dozen or so engines; certainly nothing so much as frying a decoder. It started off with it running slow and then the decoder got hot. Somehow I think the engine/lightboard is causing a short or something.

I guess I am going to send 2 decoders off to NCE for their $10 no question asked replacement.

And 1 loco off to MTH to see what the heck is going on with it...

Take care,


Brad
 

bigB

Active Member
Yes, one NCE SRJ decoder is definitely fried, and I see know other reason for it but the MTH DCC ready loco doing it. Ive had zero issues on my layout with any of my dozen or so engines; certainly nothing so much as frying a decoder. It started off with it running slow and then the decoder got hot. Somehow I think the engine/lightboard is causing a short or something.

I guess I am going to send 2 decoders off to NCE for their $10 no question asked replacement.

And 1 loco off to MTH to see what the heck is going on with it...

Take care,


Brad
Well, I finally got my two previously fried decoders back from NCE this week. My NS MTH SD70ACe works fine, but the UP one cant go 5 feet on my layout without shorting out. It is definitely wired wrong; I have over 20 dcc engines and they never short on my layout. I am awaiting MTH's response to an email I sent today on how to proceed on warranty/repair/replacement. I double checked btw that I hooked up the decoder correctly to the correct pin as shown in the MTH manual.

Not happy...
 

julienjj

Noodle is good
A little late on the topic, but have you checked if there isnt any of those "C" jumper on the mth lightboard that might be not plugged correctly ?
 

bigB

Active Member
A little late on the topic, but have you checked if there isnt any of those "C" jumper on the mth lightboard that might be not plugged correctly ?
Ive had the shell off this engine most of the time Ive owned it. Everything looks neat and tidy, I couldnt see anything missing. My other one runs just fine.

Im done fooling around with it. I paid good money for it, I expect it to work properly. I followed the warranty instructions to the T, so off it goes.

Thanks for trying though,

Brad
 

bigB

Active Member
Well, I finally got my two previously fried decoders back from NCE this week. My NS MTH SD70ACe works fine, but the UP one cant go 5 feet on my layout without shorting out. It is definitely wired wrong; I have over 20 dcc engines and they never short on my layout. I am awaiting MTH's response to an email I sent today on how to proceed on warranty/repair/replacement. I double checked btw that I hooked up the decoder correctly to the correct pin as shown in the MTH manual.

Not happy...
Well, an undate for anyone who cares.

A repairman from T&K Hobby where I sent the MTH DCC-Ready SD70ACe emailed today to say he sent the engine onto MTH to be repaired/replaced. Expect a few weeks to go by for anything to happen.

Anybody else out there had any issues with the DCC Ready version?

Take care,

Brad
 

diburning

AlcoHaulic
I personally haven't had any experiences with them as I don't currently own any MTH locos, but the club electrician had to rewire the surface mount LEDs due to some of the engines in the first run having negative common wires which the DCS decoder uses, but the DCC decoders do not. There were also phantom shorts in the locos that smoked quite a few decoders. (the club electrician was working on two of them for another club member.)
 

bigB

Active Member
I am hoping they are able to repair it or replace it. I just dont want them to come back and say 'Could not duplicate, good to go.'

It takes about 3 seconds of running it in DCC to tell their is a major problem. Im just a little miffed I had to send two fried decoders off on my dime to NCE to get their 'no questions asked' replacement (which is awesome by the way, but Im still out $24).

So Ill wait patiently and hopeful. This to me will be a true test of MTH's quality, warranty, and customer service.
 
Last edited by a moderator:

bigB

Active Member
Well, after 3 months of running fine, this same engine started shorting out again every 3 or so feet of movement. It would short out the dcc system after about 3 feet of movement. I took it off the tracks and I could smell an ozone/electrical smell. I cursed a bit, and decided to remove the decoder and pack it up to shipment to MTH for repair.

So this morning, off it went again. I have little confidence that it'll be properly fixed--when i received it after the last repair, which took 2 1/2 months, it had been supposedly completely re-motored. :mad:

At least if there is a silver lining, I'd say it would have to be that my warranty expires on it the end of this November. At least until it breaks again, I wont be stuck with a $140 paperweight.:mad:
 

Shoneburger

New Member
mth sd70`s

Engine address = 55 . Set cv55 = 55 this should reprogram engine address to defalt 3 . That`s all I know . Good luck
 




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