Nord Stage 3 – Program Up/Down pedal jack: which components belong to TIP?

[LMN2023]

Hello,

I’m troubleshooting a Nord Stage 3 (OS 2.64) with a non-working Program Up/Down footswitch.
Software causes have been ruled out (Factory Restore done, correct settings).

At the Program Pedal TRS jack:

With plug inserted, TIP and RING are both ~3.2 V in idle

Shorting TIP→SLEEVE or RING→SLEEVE reliably pulls the line to 0 V
→ so the jack, cable and pull-ups appear OK.

Near the jack I see the following components:

R52 / R53 (marked 1001, ~1 kΩ)

D5 / D6 / D3 (SOT-23, marked J3K)

LC245A buffer IC nearby (on my board labelled U65)

My question is purely about mapping, not diagnosis yet:

Which components belong to the TIP line of the Program Up/Down jack?

Is TIP → R52 → D5 → LC245A (U65) correct?

Or is TIP routed via R53 / D6 instead?

Or am I totally wrong?

If anyone has service-manual access, board-level experience, or has repaired this input before, a simple confirmation would help a lot.

Thanks in advance.

[FZiegler]

Is the pedal checked? Which one do you use? A Boss FS-6 needs a battery to work.

[LMN2023]

I use the Boss FS-6 and it works well. Also without the pedal y I tested to short the Tip with the sleeve and the Ring with the sleeve. The Tip dont work and the Ring works well. So thats not the issue.

[maxpiano]

I use the Boss FS-6 and it works well. Also without the pedal y I tested to short the Tip with the sleeve and the Ring with the sleeve. The Tip dont work and the Ring works well. So thats not the issue.

Even without the schematics, it should not be difficult to trace the signal chain from the Tip contact of the connector and up till the IC, using just a basic multimeter, to see if maybe it is a cold solder joint somewhere or some altered resistor: have you tried that?

[LMN2023]

Hi , Thanks a lot for your reply . Yes I tried to follow the route with a multimeter but I didn't succeed. I will response you later what I did maybe you can assist me.
Thanks a lot in advance.
Leon

[maxpiano]

Hi , Thanks a lot for your reply . Yes I tried to follow the route with a multimeter but I didn't succeed. I will response you later what I did maybe you can assist me.
Thanks a lot in advance.
Leon

Sure, Maybe you can post a picture of that part of the board, that can help too.

[LMN2023]

Hi,

Here are some pictures of the print.
I did some measurements with my multimeter and I showed the spots with short circuits with TIP and RING.

Thanks in advance for you help.

Leon

[LMN2023]

Hi ,

Here a update about my measurement:

The Tip is connected to U65 LC245A PIN nr 16 without pressing footswitch : 3,20 Volt
The footswitch pressed : 0Volt

The Ring is connected to U65 LC245A PIN nr 14 without pressing footswitch : 3,20 Volt
The footswitch pressed : 0Volt

More U65 measurements:
PIN 1 :0 Volt
PIN 10 : 0 Volt
PIN 11 : 3,20 Volt
PIN 17 :to GRND
PIN 18 : to GRND
PIN 19 : 3,20 Volt (strange means U65 is off)
PIN 20 : 3,20 Volt

PIN 4 all situations 0,6 volt
PIN 6 ring not connected to earth : 0,6 Volt
ring connected to earth : 0,57 Volt Momentary

The most strange thing is that the ring action works and is switching the programs well. The Tip action dont work at all.

Any help is welcome.

Leon

[maxpiano]

Well in that case could be a problem which is upstream i.e. between the LC245A and the rest of mainboard circuits (till CPU) that read that signal or that LC245A (which is an "Octal Bus Transceiver With 3-State Outputs" so basically a logic buffer controlled by the CPU) itself(?)

You should check also the LC245A output pin corresponding to the TIP actually (so if input is PIN16 output should be PIN4, according to the datasheet)

Note: if you cannot solve it yourself, please consider going to an official assistance center