How to Repair a Squareplug Patch Cable with SP400 Plugs

Introduction

If your Squareplug SP400 patch cable isn’t producing clear audio, use this guide to resolder the broken connections.

Patch cables, even well-soldered ones, are susceptible to stress-breaks at their connections. This is usually caused by repeated plugging/unplugging with regular use. A simple resolder with fresh wire ends and solder balls should bring the cable back to life.

Before using this guide, double-check that it’s your patch cable that is faulty. It’s possible the source of the signal loss is elsewhere in the signal chain.

What you need

Step 1 Patch Cables With SP400 Plugs

How to Repair a Squareplug Patch Cable with SP400 Plugs, Patch Cables With SP400 Plugs: step 1, image 1 of 1

Verify that the cable is faulty (unresponsive yellow and green LED indicators).
Yellow LED indicator
Green LED indicator
If both the yellow and green LED indicators turn on, then the cable is not the source of any audio loss. Check the pedals, amp, guitar, or power supply for issues.
If the red LED turns on, then the cable is shorting and will also require a resolder.

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Step 2

Unscrew the SP400 housing.

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Step 3

How to Repair a Squareplug Patch Cable with SP400 Plugs: step 3, image 3 of 3

Desolder the existing solder connections.
Wick the existing solder completely off of the plug connections.
Do not touch the plug or the wick directly while desoldering.
For more information on soldering, check out the How to Solder and Desolder Connections guide.

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Step 4

Cut the ends of the cable using a pair of wire cutters to expose fresh wires.

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Step 5

How to Repair a Squareplug Patch Cable with SP400 Plugs: step 5, image 3 of 3

Strip the outer insulating jacket by ~1 cm.
The Eclipse UTP Stripper works especially well for this step.
Braid the ground wires.

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Step 6

How to Repair a Squareplug Patch Cable with SP400 Plugs: step 6, image 3 of 3

Strip the inner insulator by ~2mm.
The Eclipse UTP Stripper works especially well for this step.
Braid the signal wires.

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Step 7

How to Repair a Squareplug Patch Cable with SP400 Plugs: step 7, image 3 of 3

Tin the soldering iron tip, ground wire, signal wire, and plug connections.
Do not touch the plug or the solder directly while tinning.

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Step 8

Solder the wires onto the plug connections:
Signal wire to the tip connection
Ground wire to the sleeve connection
The outer insulating jacket should slightly extend into the chamber of the plug to minimize cable movement.
Do not touch the plug directly while soldering.