Category: Guitar

Somehow, the little hex nut which holds the input jack on my Mexican Stratocaster had got loose and fallen off somewhere in the basement. I may find it someday, but there’s a lot of stuff I’d have to move to do that as I have no idea in which area it fell. Ok, well, it was probably due for a replacement anyway, as it buzzed about as though there was some issue with grounding.

Search for a replacement

I spent a day first looking for replacement hex nuts¹⁾It took me a while to find the likely specs of the nut in question! but as I was concerned about getting it right, and given the cost and inconvenience in the COVID world, I decided to just replace the whole jack. The guitar, a gift from my brother many, many years ago, probably could do with a new jack; it didn’t seem to be grounding properly, at least, that’s what I assume from the buzzing sound I got when I wasn’t touching the strings.

It took a while, but I eventually discovered that I could get 10 replacements for the same price as a single one through Amazon; eventually, I settled on these, at CAD 9.99. The order was placed on 13 March 2021 and they arrived on 22 March. Not bad at all!!

I should have paid more attention, I suppose, because it turns out that these were not identical to the one being replaced, as I’ll explain shortly. But this was the most cost-effective option, and all was well in the end.

The repair process

Life being what it is, I didn’t get around to the actual repair until today, 23 May, so two months later! Never mind ….

Obtaining a replacement

Here are images of the old jack and the new replacement. As you can see, the old jack, being a standard mono jack, had only two connections, while the ones I bought, being TS jacks,²⁾I did try to find information on the intended purposes, but though there is a lot about TS and TRS cables, no one really seems to discuss the jacks. had three.

Comparison and diagnosis

Rather than rely on outside sources in this situation, I decided to conduct my own diagnosis in order to come up with a solution. To this end, I got out my handy multimetre, shown below.

I set it measure ohms (i.e., resistance) and checked for connectivity between the lugs and the shaft and flanges,³⁾Sure, I could have eyeballed it, but my eyesight isn’t that great with the tethered floater in my right eye, and may as well have some fun being scientific. starting with the original—before removing it! And since the two flanges were in contact in the TS jack, I inserted a piece of paper between them so that I’d be able to test the lugs without dealing with short circuits.

I determined the following:

• for the original mono jack,
  • the black wire’s lug was connected to the shaft (ground)
  • the white wire’s lug was connected to the flange (primary lead), and
• for the replacement,
  • the longest of the three lugs was connected to the shaft (ground)
  • the middle lug (both in terms of position and length) was connected to the flange (primary lead), and
  • the shortest lug was connected to the inner contact flange seen in th picture above.

So it became clear that the black wire was to be soldered to longest lug while the white was to be soldered to the middle lug. The third lug was immaterial for my purpose.

Actual repair details

Repair was straightforward:

• unsolder the old connections
• solder the wires to the appropriate lugs on the new jack, carefully
• attach the new jack to the ferrule⁴⁾This being the housing from which it protrudes.
• reattached the assembly to the body of the guitar.

The parts involved in the the reattachment are shown in the next image, which highlights the order of assembly, most importantly that the washer is placed between the ferrule and the hex nut.

And that was it! Like new!