How I Fixed My GNX 4 Guitar Processor for $2, part 1

So, for the last couple of years I’ve been using one o’ them guitar multi-effects processing workstation thingies made by companies like Line 6, Boss, etc. etc.  In my case, it’s a Digitech GNX4.  Looks a lil’ something like this:


The GNX 4 in Working Condition

A mostly harmless tool.

As a live tool, I find it to be a little bit dodgy, but it’s been a great boon to recording.  It’s got very natural-sounding amp modelling and, when you use the X-Edit software (in my case, under emulation in WindowsXP on my MacBook Pro — thanks loads for the sterling OSX support, Digitech!) it’s capable of delivering a frankly amazing array of sounds and textures.

I picked it up shortly after we finished recording The Luxury Problem, and used it heavily during the recording of Signifying Nothing.  As we’ve been trying to complete An Index of Maladjustments, however, I began having problems with the GNX4.  Specifically, its connection to the computer’s USB port — critical for both recording and adjusting the parameters of the sound — became first unreliable, then nonexistent.

I tried using a USB hub between the GNX4 and the computer.  That worked for a while, but then it too refused to connect.  I tried different USB cords without any luck.  Then, finally, I looked that the actual USB port on the back of the GNX4 itself.

Aw, shit:

You can't get there from here.

You can't get there from here.

Now, what you’re seeing there is, on the right, the way a functioning USB port of the type used in the GNX4 should look.  On the left, you see what the port in MY unit looked like.

You’ll notice the difference, I trust.

Somewhere along the line, the little plastic nub that presses the wires connected to the GNX4’s circuit board against the contacts on your USB cable got knocked out.  No nub = no connection.

With recording deadlines looming, I felt like I was hosed.  And with my budget, I didn’t feel like shelling out a lot of $$$ to have someone, erm, qualified take care of it.

So I decided to do it myself.  In the end, it cost me about $2 and an hour of my time.  And now I need to return to the mixing desk, so I’ll continue this story of desperation and ultimate triumph next time.

Have you ever found an essential piece of equipment had gone rogue, either through neglect or abuse, at PRECISELY the wrong time?  How did you deal with it?



  1. So…where’s the rest of the story – Part 2 – where you tell how you actually did it? I have the exact smae problem with my GNX4 and I’d like to know how to fix it – a little help here?

  2. Heys guys! I had the same problem. Bent the USB cable with my foot. There’s a post somewhere on some forum that shows the part number for the USB connector from Mouser Electronics. I soldered me in a new one and it works fine. Now I think I’ve got to re-solder the power connector and possibly the line-in(s). In Canada, we’re supposed to be able to send it to Erikson Audio who will fix it all up for $85 bucks plus shipping. Digitech gave me their number.

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