# ANOTHER bad decoder from QSI?



## alfischer (Mar 8, 2010)

Well, I returned the bad decoder we were discussing in anothe post and QSI got aother with steam sound back to me in 8 days. Excellent support especially considering I live in a rural area with lousy mail delivery. DEAD. Nothing out IF the receiver is attached to it. Tried it with 2 different receives and same results, All 3 receivers work with another decoder. If I do not connect the receiver it produces sound and cam be reset. Anything I am doing wrong?


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## lownote (Jan 3, 2008)

I've never had a bad receiver from QSI. No offense meant, but I have to wonder if there's some user error here. Can you explain your setup again? Are you saying that the sound quits when the G wire receiver is connected? Did you make sure to "wake up" the loco by pressing 6? Are the frequencies set rght? 

when the receiver is not connected, is it powered by straight DC?


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## alfischer (Mar 8, 2010)

Last night I opened the replacement from QSI and plugged it in to the board. It produced sound. Powered it off and plugged in the receiver. No sound. Unplugged the receiver and sound when decoder is powered up. Plugged in the receiver and no sound when powered up. Cable IS plugged in correctly. Worked with another decoder. 3 receivers tried. same results. One decoder works the new one doesn't.

This morning, I tried it again. Now it is working. No, I had not partaken of a bit of the bubbly! I guess I will have to see if it continues to work or is somehow intermittent. 

USER ERROR? Very possible. I did the '6' key thing. I did double check the cable and exchanged it with another decoder. Results were always the same. Until this morning. Now it is working. I dunno!

Basically, any on of the 3 receivers when plugged in caused the decoder to produce no sound. Well, at least it's working now.


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## Greg Elmassian (Jan 3, 2008)

Don't always expect it to make sound at power up. Normally it needs F6 to do that. On mine, some make sound at power up, like when I put it on the rails, but most are silent until the F6 startup. 

It's easy to plug the cable in backwards, but then receiver would never function. You tried different receivers, but did you try different cables between the receiver and the board? Are you sure the cable is seating all the way in? I'm guessing a flaky cable. 

Those are my guesses. 

Regards, Greg


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## alfischer (Mar 8, 2010)

Tried with 3 receivers with their own cable. Plugged in right. Checked pwr at the board input. Went to bed. Tried this AM. Worked right off. The other decoder plugged into the same board worked. I MUST have been doing something wrong. Again. Now working, and always makes sound at power on state. I'm gonna call this operator error for now. Learning curve.


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## Tenwheeler (Mar 5, 2010)

Al,

It is quite possible there was (is) some contact oxidation involved with the card edge contacts and/or the ribbon cable connector. Sometimes [/i]the simple action of seating and reseating the connector on the card a few times is sufficient to improve continuity in the junction area.

There is an excellent product called Rail-Zip [/i][/b]produced by Pacer Technologies[/i] and available in most hobby stores that is specifically designed to eliminate accumulations of oxide. It is marketed as a rail and wheel cleaner, which it does very well. Rail-Zip[/i][/b] can also be used as a contact cleaner, to include gold plated contacts in all electrical applications. It does not react with plastic or nylon parts. Apply with a clean cloth on the card edge contacts and polish dry with a clean area of the cloth. Once clean, apply a thin film on the clean contacts with a clean area of the cloth. This film acts as an oxidation retardant. On the ribbon connector, accomplish the same process with a good cotton applicator (Q-Tips work great).
This product can be used in any model railroading electrical contact application – motor contacts, lighting contacts, nickel silver rail, etc.

If you suspect the malfunction is the ribbon cable or connector-to-ribbon, troubleshoot with an ohm meter. If you don’t have access to an analog or digital multimeter, any of the inexpensive automotive type meters will get the job done.

Good Luck!

Jerry
“Pour the coal to her, she don’t leak”[/i]


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## Greg Elmassian (Jan 3, 2008)

I think Jerry is on the "right track", also the action of putting the cable in and out can serve to either wipe the connector clean or move a bit of debris along one of the pins... blow a bit of compressed air into the connector socket too. 

You could still have a flaky connector or cable... 

Regards, Greg


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## alfischer (Mar 8, 2010)

Very possible. I have fixed many computers by simply reseating cards. Also the tinned type of contact has been problematic. And with the new solders being used, even worse. When I get to town I will pick up some RAIL ZIP. 

It does seem strange that it caused to decoder to not operate at all, but came with when the receiver unplugged. Not likley a flakey cable as I tried it with 3 receivers and 3 cables. Possibly a bit of debris on a pin or some oxidation. 

At least it's working now.


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## Greg Elmassian (Jan 3, 2008)

Plugging in the cable causes it to take commands from the Linx transceiver (it is bidirectional), so maybe it "Sees" the transceiver, but the commands are garbled? 

Maybe the QSI just detects the power draw to know the transceiver is there... but the data lines could be not so good. 

Regards, Greg


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