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switching board question

Started by zgrav, May 16, 2018, 03:31:08 PM

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zgrav

    A quick question based on just a few minutes troubleshooting the switching board for the Blueprint pedal since I think the relay for the switching board might be defective.  The audio and switching boards are fully assembled and wired together, but have not been installed in the box.  The wiring connections and positive and negative voltages on both boards look OK, including the 5v power going to the pic.  The LED turns off and on when the momentary switch is pressed.  Plugging in a guitar and speaker, the bypassed signal is OK, but the relay does not switch to the in/out connections that go to/from the Blueprint board when the switch is pressed and the LED comes on.  Continuity exists between the in and out jacks even when the LED comes on when the switch is pressed.  When pressing the momentary switch, I can only hear the relay click with every other switch press, while it remains silent on the other (unlike the soft clicks I can hear for each press on other switching boards).     Is there is another plausible thing to check that would have this same symptom before I unsolder the jack and relay to put in a replacement?   

fair.child

Check the IN connection when the relay clicks to the Blueprint board. It might be good as well to check your solder joint between the Blueprint IN and the Relay board IN.

zgrav

Thanks for the suggestion.  The solder connections for the input from jack to board, and in the wiring between the boards tested OK but I reheated them as well.  Did not change the problem.  The input from the board is also remaining grounded at all times, which seems consistent with the relay not switching the signal into the board.  I did check to see if the pic would change to the momentary operation and it does seem to work, but does not change what the relay is actually doing.  At the very least I plan to pull the jack so I can take a look at the relay connections to the board.

zgrav

My problem with the switching board was with the relay, but only because I had ordered the non-latching version.  Note to self (and as a heads-up to others):  the "L" in the part number is very important.  It took looking at the different versions of the relay in the Panasonic datasheet for me to finally realize I was using a different part than called for.

sarde

Can you hear the relay make any noise when you hit the footswitch? I can hear my relay engage if the pedal case is open. That would seem to be a easy thing to do in order to determine if the relay is working at all.
Check out some of my projects over at https://pendragonguitarworks.wordpress.com/

zgrav


It was only making the right clicking noise (like the other VFE pedals I have assembled) with every other press, and not actually switching the relay away from the input/output jacks.  I have the right part that I plan to swap into the board in the next day or so.