F7A sound value deisle shell removal

[mr. mick]

Trying to figure out how to remove the shell from  a NYC Sound value F7A.It doesn't slip off as I expected; complicating things is that the front coupler needs to be removed before the shell will come off, not sure how to remove that coupler. Back coupler looks like it s part of the chassis.  Any suggestions would be helpful. I'm thinking some of those screws on the bottom might be involved, but I am not sure.
Thanks,

Mr. Mick

[Len]

Remove the front coupler. Then remove the two screws holding the fuel tank in place and take the fuel tank off. This will uncover either two or four screws holding the shell on. Remove them and the shell will come right off.

Len

[jbrock27]

I am sorry Len, I am with you up to the point of removing the front coupler but not after that.  Removing the fuel tank's screws will allow one to losen and remove the motor cradle not the shell.  There should be 4 deep holes, 2 in front and 2 behind the fuel tank, that have screws in them that go through the chasis. 
These are the ones that need to be removed in order to remove the shell.  These screws end up screwing into 4 plastic posts molded into the shell.

http://www.bachmanntrains.com/home-usa/dwg/dwgs/HO_F7-A_Sound.pdf

[Len]

The Bachmann diesels I own all require removing the 'fuel tank' to access the body mount screws. Looking at the exploded diagram, I thought the SoundValue diesels (I don't own any) were the same. Live and learn I guess.

Len

[mr. mick]

I removed the two screws securing the fuel tank cover, no screws behind them, so I reinstalled the fuel tank cover. Since I already had the screwdriver in my hand, I removed the four screws set deep in the chassis, and that allowed the shell to be lifted off, revealing the Soundtraxx circuit board. All this because my friends loco only would sit on the track and make noise like an idling diesel. No lights, no response to controls, etc.  I tried to program on the main to assign ID # 3, and as far as I can tell, it did not work. Then I tried resetting CV-8 to a value of '8' ( programming on the main with MRC Prodigy Advance2 system) - program in the eight, de-energize the engine for five sec, and then re - energize it.  No response; but after about 6 or 7 seconds, the idling diesel sound came back on.  I noticed that after I removed the shell ( and saw that the wires were all soldered in place, no broken or loose connections that I could see ) thate there was a bright red light on the circuit board when the board was energized.

My conclusion is that the decoder is Kaput.  Anyone have any experience troubleshooting this problem?

Mr. Mick

[rogertra]

I removed the two screws securing the fuel tank cover, no screws behind them, so I reinstalled the fuel tank cover. Since I already had the screwdriver in my hand, I removed the four screws set deep in the chassis, and that allowed the shell to be lifted off, revealing the Soundtraxx circuit board. All this because my friends loco only would sit on the track and make noise like an idling diesel. No lights, no response to controls, etc.  I tried to program on the main to assign ID # 3, and as far as I can tell, it did not work. Then I tried resetting CV-8 to a value of '8' ( programming on the main with MRC Prodigy Advance2 system) - program in the eight, de-energize the engine for five sec, and then re - energize it.  No response; but after about 6 or 7 seconds, the idling diesel sound came back on.  I noticed that after I removed the shell ( and saw that the wires were all soldered in place, no broken or loose connections that I could see ) thate there was a bright red light on the circuit board when the board was energized.

My conclusion is that the decoder is Kaput.  Anyone have any experience troubleshooting this problem?

Mr. Mick

Not knowing your track arrangement but programming "On the Main" is not a good idea as unless you remove all your locomotives from the track except the one you want to program. If you do not remove all locos, you will reprogram all DCC locos at the same time with the same settings.

Best to program locos on a separate, independent, isolated programming track.

Programming on the main is best used only to program and un-program consists.  All other programming should be done on a programming track for the safest results.


Cheers

Roger T.

[jbrock27]

The Bachmann diesels I own all require removing the 'fuel tank' to access the body mount screws. Looking at the exploded diagram, I thought the SoundValue diesels (I don't own any) were the same. Live and learn I guess.

Len

Funny, all the ones I own, come off in the manner I described LOL!

No worries Len, you have helped me on numerous occasions.

[mr. mick]

Thanks for the reminder, roger.  I avoid that (now) by using a programming track that can independently be connected either to 'main" or "program" connections, without powering the main track.

[bapguy]

If the decoder makes sound, I don't think it's kaput. With the loco off the track, take an OHM meter and check for continuity on the tabs on the decoder for the motor. No reading could be a bad solder joint or broken wire(s) to the motor. Check for continuity to the decoder and wheels front and rear both sides and all wheels. With the shell off reset the decoder using program on the main. Watch to see if the motor turns or the loco jerks a bit. This indicates the decoder received the signal. When I do this, I lift one side of the loco off the track and count to 30, then replace the loco. The head lights or light on the decoder should flash several times indicating the reset took.  Try programming a short address such as 03. If this does not work, try a long address such as 300. Your system might not have enough oomph to program the decoder. My friend has an MRC system and I bring my Digitrax over to program his locos. Hopes this helps.   Joe