Nepos first Test > No Signal

[Nepo]

Hello all,
I'm purches a Full Kit , and build it after the instruction ( theoretically easy ).
I connect my new box via USB with my computer, switch box on, and the LCD is fine, the potis work too when I turn it.
To test the jacks ,I connect a piezo with a stereo cable. When I touch the piezo there is no signal on the VU.
The red LED is still out. I tried all inputs with the same result.
Any tips to locate the problem?

br

Jörg

[dmitri]

Most likely you connected the piezo to wrong wires. Make sure you use correct ground wires. Take a picture of where you connected the piezo to the flat cable and, if you unplugged the flat inputs cables after unpacking the parcel, how you plugged the cables back.

[Nepo]

Hello,

here some pics about the connections, hope you can see something.

I try most of the jacks and change tip and ring but I got still no signal.

[ignotus]

You're connecting the piezo to tip and ring: wrong.

On a stereo input:

Piezo 1 goes to tip and sleeve

Piezo 2 goes to ring and sleeve

The ceramic part of the piezo normally goes to tip/ring and the brass part to sleeve, though I don't think it matters much.

[Nepo]

I test different combination (Ring, Sleeve, Tip) with the piezo > no Signal.

At last I connected a new Roland CY5 Cymbal> no signal.

I think something with the connection is wrong....

Can somebody see something on the pics?

br Jörg

[dmitri]

Show how the flat inputs cable is connected to the board and mark two wires on it which you believe are ground wires.

[Nepo]

Ok, I marked between 15 & 16 in red...

The upper and the lower jackrow are connected on sleeve with the longer red cable on the left site.

Pin 1-4 are not used.

br

Jörg

[dmitri]

1. Did you test it with only one piezo?
2. What happens on the LCD if you touch one of the input pins (which is not connected to a piezo) with something metallic, e.g. tweezers, held with a bare hand? You may want to hold another hand close to some electromagnetic signal source, like a bulb of a lamp, to induce parasitic signal on the input.

[Nepo]

1. I try it with
-a brand new CY5 cymbal
-two different single piezos
-without stereo cable - connected direct on the jackpin > no sigal

2. as you suggest I touch the jackpin with an little fullmetal srewdriver, and I got a short peak on the VU and red led.
The signal is not permanent only a peak, even when I let srewdriver on the pin.

[dmitri]

2. as you suggest I touch the jackpin with an little fullmetal srewdriver, and I got a short peak on the VU and red led.
The signal is not permanent only a peak, even when I let srewdriver on the pin.

I guess by the jackpin you mean a pin on an input jack and not the pin on the board. In this case:
1. Unsolder one input wire from one input jack.
2. Unsolder both ground wires from the jacks.
3. Solder a piezo to this one input wire and one of the ground wires.

After that tap the piezo. What do you see on the LCD? If you don't get a VU meter signal/MIDI LED, with a multimeter test for continuity between one of the ground pins on the board and both ground wires on the flat inputs cable.