Marshall Guv’nor Repair

Recently a friend of mine was having trouble with his older Marshall Guv’nor pedal (black enclosure). I wanted to document this repair, in case any others run into this problem. The early symptoms was shorting out. Kicking it would sometimes get it back to playing, but obviously that’s not an ideal solution. The first possible suspect was with the DC power jack. It was loose, but noticed that 2 out of the 3 jacks were missing their mounting nuts causing the top PCB (which connects the pots to the main PCB) to be loose.

I took the pedal apart and inspected the solder connection of the power jack and it looked solid. Thinking this would be as simple as finding compatible nuts and secure that board, I tightened the connections and reassembled the pedal enclosure. First test, sounded great until we kicked the pedal while it was engaged and sure enough, the pedal cut out. So at this point it’s most likely not a power issue. I started tapping wires and eventually came back to the input and output jacks. Wiggling the input and output plugs I could make the pedal short out. The solder connections for the jacks were fine and I saw no motion on the jack itself but there was a hair of wiggle room within the jack itself.

Doing a little Googling, I did see mention of those jacks going bad and this pedal has definitely seen some action throughout the years. I have plenty of Switchcraft jacks laying around, but noticed these are the 9 pin low profile jacks. I’m left with a couple of options at this point. If I go the Switchcraft route I would need to do a re-house since those jacks do not fit in that area at all, plus I would need to really understand what the signal path is all about. I opted to find replacement jacks.

I ended up buying Fender Jack Phone Stereo 6.5mm Part #0059922000. I saw that they were built a little tougher and the dimensions matched the originals. These jacks are a little pricey though – coming in at $7.95ea. I bought mine at Darren Riley’s (click here for the part) and they arrived quickly.

For this repair I thought I would replace all the jacks including the ‘loop’ jack. The first process is to desolder the current connections. This can be tricky depending on your skill and tools. I would highly recommend a desolder bulb or suction ‘pen’. I’ve always had terrible luck with braids and wicks, but whatever works for you. If you have no desoldering tools.. STOP and get something first.

The important tip for this is to take your time, don’t force things by prying too hard or pulling the component. By taking your time you’ll ensure a clean removal while not damaging the board.

Here is a shot of the board with all the connections I will need to desolder (total of 23 connections).

As you can see that 2 of the jacks use all 9 lugs (Input and Loop) but the output only uses 5 lugs. I clipped the extra lugs from that jack. Make sure you verify before clipping anything (“measure twice – cut once” rule applies here).

Here is a shot of the original output jack with my new jack with clipped lugs:

After re-soldering all of your connections (be careful to not create shorts with your soldering, but keeping the solder enclosed within the bounds of their solder pads) it’s time to secure the jacks. These jacks have plastic threads, so be sure to NOT over-tighten. I like it tight, but over tightening will lead you to do this all over again.

Here is the shot of the Marshall Guv’nor with the old broken jacks removed.

I was pleased to get the Marshall Guv’nor back together, and it works perfectly. It passed the “kick” test. I’m guessing the jacks were actually broken inside or the contacts were not seated well within the jack itself. Definitely the new jacks felt tighter in general.

This was an easy repair, but if you’re not fluent in soldering, specifically with desoldering, this could be a little tougher for the novice. I can’t state enough – take your time and it should work out great.