Troubleshooting a Loksound in an IM SD40-2

[squirrelhunter]

I've got an odd problem with an ESU decoder in an Intermountain SD40-2. I did a factory reset by setting CV 8 to 8 to start with, then used JMRI to set the decoder address. I read the sheet with the sound levels, and decided to fire up the locomotive to hear the sound level to start adjusting things.

I selected the loco, and I can turn the headlight on and off, but the loco does not respond to any of the other function buttons on the Power cab. The CV's still read on both the power cab and JMRI, but beyond the headlight it wont do anything.

I tried another factory reset, and I still have the same issue. I'm guessing some CV is messed up, since the decoder still reads CV's and I can still select the loco and the headlight works, but nothing else seems to work.

[skytop35]

Most likely the motor and speaker contacts under the circuit board are not making contact with the board. Remove the board and bend up the 4 contacts you'll find and reassemble. This should solve the problem.

[peteski]

What was not mentioned is whether any sounds (including the prime mover sound) work, or is the model silent?  That would be a good nugget of info to have for troubleshooting.

[squirrelhunter]

Skytop35, I'll check the speaker and motor contacts.

Peteski, the loco will not make any sound nor will it move. The bell and horn do not respond to either the bell and horn buttons on the power cab or to pressing F1 or F2. Same for the prime mover, pressing F8 yields nothing. F0 gets the headlights to turn on, and they respond when I change direction, but I get no movement when I turn up the throttle.

[peteski]

If there is no sound or movement (yet the on-board LEDs work) then I agree with Bill that the motor and speaker contacts on the bottom of the decoder seem like the most likely suspect.

[squirrelhunter]

So I double checked the contacts, and sure enough, both on one side were noticeably lower than the one on the other side. One I adjusted them all up, everything worked like normal.

Thank you to peteski and Sytop35!

[carlso]

Just a question. I know 1st hand, do not ask how, that these contacts are pretty fragile. Must be very careful with them. Next time I shall place a ball of solder on top of the 4 contacts and not try to pry them up. Good idea ?

Carl

[RBrodzinsky]

Just a question. I know 1st hand, do not ask how, that these contacts are pretty fragile. Must be very careful with them. Next time I shall place a ball of solder on top of the 4 contacts and not try to pry them up. Good idea ?

Carl

Carl, yes, I did that on the IM’s that folks asked me to work on for them (don’t have any of my own).