Latest run of Intermountain F7s, decoder/light board style?

[Ed Kapuscinski]

Over the weekend, I got a deal on some TCS IM F unit decoders.

Great!

I just bought a pair of PC Fs, and I needed decoders for them, so the timing was pretty good.
However, because they were opened packages, they can't be returned...

But, I did some quick googling, saw that the IMF4 was indeed the one I'd want, since my Fs were pretty late model, and "Plug and play" would be the way to go. Right?
http://www.tcsdcc.com/Customer_Content/Installation_Pictures/N_Scale/Intermountain/F7A_B/F7A_B.html

Wrong.

Turns out, after I open the engine up, it actually looks like this under the hood:
http://www.tcsdcc.com/Customer_Content/Installation_Pictures/N_Scale/Intermountain/F7A_B/NF-Version/F7A-NF.html

I'm rather annoyed at Intermountain for their lack of consistency, and also, for going backwards from a plug and play to a wired design.

Sure, I should've opened the engines up first before buying decoders, but you generally should be able to trust things like this without having to physically verify them.

I don't need to measure my oil filter before I go to the store to get the one that fits: there's a guide that explains it.

Why does the model railroad and DCC world have to be so inconsistent and frustrating?

Anyway, I wanted to point this out to everyone, so that, if they're shopping for IM F unit decoders, open your actual engines up and look, and don't rely on release dates to guess.

At least, I think, I can still make them work.

[Bendtracker1]

Yep they'll still work Ed.
You just need to solder a strip of wire to the tabs and run them up through the board.

I heard that the little brass stand offs on the original boards would be inconsistent when installed and some would touch the frame if the board wasn't installed just right. 

[R L Smith]

Resurrecting an older thread, as I am in the midst of putting decoders into an ABA set of the new Intermountain F3's.

Thanks to Ed's warning, I knew to order the correct TCS boards from my LHS.  However, I think these are a bit pricey, considering there is no wire harness and no LED lights on the boards.

Anyway... I started with the B unit and the install went pretty well until I went to the programming track - got en error message.  Back to the workbench to re-inspect my soldering; no visible problems.  Got out the DVM and found the black motor wire was shorted to the chassis somehow.  I ended up tearing the loco down where I found that the black motor wire where it was soldered to the motor tab was making contact with the frame.  No problem in DC, but a big one in DCC.  I was able to slip some kapton tape in there and fixed the problem. The B unit runs fine now.

Moved on to one of the A units. This time I used the DVM before going to the programming track, and once again the black motor wire was shorted to the chassis.  Tore the engine down and found the same issue - the motor tab was shorted to the frame, and kapton again did the trick.

Now, however, the engine runs great but I have no headlight.  I wired the headlight as shown in the TCS instructions, but it appears to be reversed from the original Intermountain installation.  (I've sent a note to TCS tech support to ask about this.)

Just wanted to let folks know about the motor tab shorting problem...

RLS

[Ed Kapuscinski]

Thanks! I was just contemplating tackling these. Glad I didnt.

I don't understand why this stuff is always so hard. It shouldn't be rocket science. But, apparently...

[peteski]

Thanks! I was just contemplating tackling these. Glad I didnt.

I don't understand why this stuff is always so hard. It shouldn't be rocket science. But, apparently...

I have a feeling that his has everything to do with sloppy assembly procedures and lack of quality control. But I could be wrong - it might be a design flaw.

[carlso]

Peteski,

I think you are 100% right on with both comments (sloppy assembly and lack of adequate QC ). I am speaking with first hand experience as my guide. Actually, I think there may be one other and that is poor design. Why did they change a mechanism that had worked perfectly for several years. Oh, I forgot, to save a few pennies per unit? ? ?

Carl

[R L Smith]

I'd say this is more due to sloppy assembly procedures than anything else.  These units would have worked fine in DC and would therefore pass any operational QC checks.

I plan to get to the third locomotive later this week. Once I know if this is 2 out of 3 or a strikeout, I will e-mail Intermountain and advise them of the issue.

Has anyone else installed the TCS IMN4-NF and can tell me about the headlight wiring? TCS hasn't responded to my inquiry yet.

Ron

 

[Roger Holmes]

I mentioned the frame shorting issue here a while back.  I fried two micro-Lok Sound decoders trying to do the B unit sound install that Bill Denton had in a magazine.  Absolutely no issue with Bill's method.  In an ABA set there was one where both brush cap solder blobs shorted the frame and two where one side on each had solder blobs that shorted the frame.  I called IM and they acted surprised .  I could have put Kapton tape on them myself (or filed down the blobs) but I wanted IM to see the shoddy soldering on the units that I bought so I mailed them directly to IM.  They came back with no explanation but each unit had Kapton tape over each brush cap 

Looks like quality control has not improved.  Yes, if the factory test runs them on DC no issue shows up but there has to be a lot of fried decoders out there for the unsuspecting DCC installer.

And, yes, frying one expensive sound decoder was IM's fault.  Installing a second without finding the source of the short was my own impatient fault.

[peteski]

Looks like quality control has not improved.  Yes, if the factory test runs them on DC no issue shows up but there has to be a lot of fried decoders out there for the unsuspecting DCC installer.

And, yes, frying one expensive sound decoder was IM's fault.  Installing a second without finding the source of the short was my own impatient fault.

Strictly playing a devil's advocate. IM could blame both decoders burnouts on you. Why? Because, while their QC did pass incorrectly assembled locos, decoder installation instructions always instruct the installer to check for shorts between the track leads and motor outputs (and function outputs).  If you didn't do that then you missed an important step during decoder install.

Like I said, I'm not trying to blame you - just bringing to light another perspective.

[R L Smith]

Well, fortunately for me I did not fry a decoder, but sure wish I'd noted Roger's comments when they were made - would have saved me some time.

So here are the final results: we have both a sloppy assembly issue and a QC problem. 

I fixed the headlight problem on the first A unit by swapping the headlight wires.  The photo on the TCS website wasn't clear enough for these aging eyes I guess.

I worked on the other A unit tonight, and found no shorts.  The decoder install went smoothly and everything works. No Kapton required. 

Now the QC problem: the last A unit is missing the green plastic insert that is supposed to represent the cab!

Finally, these units run great and will probably pull the paint of the wall. The mechanisms are well-matched and I don't think I will need to attempt any speed matching. The shell detailing is great (except I knocked off one of the free-standing windshield wipers when I was removing the shell) and the Lackawanna paint scheme is well executed.  Considering what I paid for these and the decoders, there isn't much hobby budget left for this year, but overall I'm happy to have these running on my layout.

RLS

[Roger Holmes]

Peteski, you devil-- I guess I have lived on the edge for too long by not checking for shorts before installing decoders and this time it bit me in the butt for the first time in 50-60 installs.  And I'm a guy who won't go gambling because I hate to lose money    Electronics is definitely not my forte.

Moja wina!

[peteski]

Moja wina!

Oh Roger, you made me laugh! Thanks!