I recently purchased a secondhand fleet that is sound/dcc equipped. Long story short I decided sound equipped isn't for me. While transferring this P2K GP18 chassis to an ICG shell for resale I discovered that some of the solder joints needed to be touched up. None of the joints are loose now, but the sound doesn't work anymore. I tested it on my layout and the headlights turn on and it runs properly. Before I took off the NS shell to transfer the chassis everything worked fine. The kicker is that I touched the leads of the speaker to the connection on a different unit and it worked properly. So what do the gurus here think: something reconnected to the wrong lead or dead sound chip? I have nil for info on the decoder as far as model and manufacturer. Hope these pics help.
Do you have DCC and are you trying to run the engine on the correct address? Some sound decoders don't turn on until you dial in the address and advance the throttle slightly. Perhaps the sound has been muted. F8 is the QSI mute command.
Yes, I have DCC and the decoder is set for the correct address. I'll look into that on the mute command ..... every decoder that I've installed is Digitrax.
Any other thoughts before I set CV #8 to 8 and start over from the manufacturer defaults?
Other info that may help: all I did for reprogramming it prior to this issue was to change the address from 0004 to the default of 0003 courtesy of CV 8, and then reprogramming it to its new road number of 9405.
If it's a P2K with factory installed sound and not someone else's work, it is a QSI decoder. If the locomotive runs on the address you have it set at, and the headlights work okay, then the problem with sound is either a blown decoder or poor speaker connections. Setting CV 8 to 8 is not the reset function for QSI decoders. You'll need to download the QSI Technical Reference Manual from their web site to find out how to reset the decoder. Some of them have a reed switch that you reset with a magnet, and some have a jumper that has to be moved to perform the reset. It all depends on exaclty which QSI decoder your loco has in it. If your DCC system can read back CV values, you'll have to query CV 7 to get the decoder version number, which will be in Hex notation, and then find the applicable technical reference document.
Looking at the photos, I think that's a QSI sound decoder, but a very early version.
Strange, I've just had the same problem develop in a GP9 and SD9 by P2K. I think it's the wire connection on the original board.
The Cedar Branch & Western--The Hillbilly Line!
Also those solder joints are a bit balled up. Take a good look to make sure there are no solder bridges/shorts between terminations. Especially between the one's to the speaker. Then hit F6 a few times to make sure you aren't muted. If you don't know what decoder you have go into program track mode and see if you can read the manufacturers ID number.
Springfield PA
NS AS-416Other info that may help: all I did for reprogramming it prior to this issue was to change the address from 0004 to the default of 0003 courtesy of CV 8, and then reprogramming it to its new road number of 9405.
This is probably not relevant to your problem but I'll mention it anyway. On my NCE system 0003 is a long address, not a short one. So if you actually were able to reset the decoder using CV 8, it would have reset to 3, not 0003. But if it is a QSI decoder than CV 8 won't reset it anyway.
I'll also double check the solder joints for bridges/shorts. I'll have to hit up my LHS since my DCC system can't read back CV data and IIRC the one on their display layout can.
Edit: Quick random thought - if it was a QSI decoder as suggested then the CV8 reset I had already done shouldn't have worked, therefore I hypothesize it is not a QSI decoder.
Once again if you can read CV8, manufacturers ID you can tell what you're working with.
Hamltnblue Once again if you can read CV8, manufacturers ID you can tell what you're working with.
... and I do that how with this?
It will let me input the data, but has no way to read and display the data in a CV (that I have found anyways)
In all seriousness though, I did see that before. That is why I mentioned that I will need to use a higher end DCC system than the one I currently own since mine does not have this capability.
It maybe a bit of a stretch but try reprogramming the decoder from the default address # set it on your program track and first give it the #3 default address (if I am not mistake I believe 3 is pretty much the universal default number but not having any QSI decoders I can't say for sure) and then see if everything functions properly If it does then assign it the address it had before. It's been my limited experience that it's not all that difficult for a decoder to loose only some of it's functions and not the rest and it doesn't take a heck of a lot to make it happen either. Possibly a cold solder joint was the culprit and by removing the shell you disturbed the force fit connection.
That is NOT a QSI decoder. The second photo from the original post though shows what looks to me like wire melting/excessive heat applied near the lower left corner - if there are any components between the black wire and the chip they are probably toast, and the lower left pin of the big chip may also no longer be connected to the circuit board - it doesn't take much with surface mount chips to 'disconnect' them from the circuit. You also need a very fine point low wattacge solderign iron to work on things liek that. You might try carefully unsoldering the wire and connecting it again making sure not to hold the iron on too long and also not to ball up a large amount of solder so it bridges any other circuit traces. If the iron isn't flowing solder instantly, the tip is too dirty or shot - it shoudl be very shiny with no dull spots, otherwise you have to keep the heat on far too long. With decoder-size wire and small solder pads, it really should take less than a second to attach the wire.
--Randy
Modeling the Reading Railroad in the 1950's
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