JHS pedal repair – Sweet Tea V2

JHS pedal repair

This is a JHS pedal repair for a good friend and guitarist who now works in London. It’s a two pedal overdrive. Its a Sweet Tea V2 – sounds great!

The pedal had been damaged by the use of the wrong power supply. It was a fairly simple repair to complete. No schematics are available for JHS pedal repairs, but there’s not much new under the sun in distortion pedals. The only funny thing about this one is that they have a top copper pour for V+ and a bottom copper pour for GND. It’s normal to pour GND only so that had me confused for a few minutes.

If you need a JHS pedal repair, please get in touch.

Dunlop MC404 CAE Wah pedal repair

Dunlop MC404 CAE Wah Pedal repair

In October last year I fixed this wah pedal repair for a lincoln customer. The pedal would not turn on, possibly as a result of the user plugging the wrong power supply in.

Often pedals aren’t economical to repair, but a unit like this is normally worth it. In this case it was a fairly simple repair, completed within the first hour and the completed wah pedal repair cost only £35.

if you have a wah pedal repair, please get in touch.

Broken footswitch repair – MXR Carbon Copy

Broken footswitch repair

This broken footswitch repair was sent to me because the owner suspected that his pedal had the ESD problems that I’ve documented elsewhere. 

Actually, the footswitch was broken by mechanical use. This is comparatively rare – MXR use quality ‘Alpha’ parts for their footswitch.

The unit was soon fixed, and shipped back to its owner, in Dubai!

If your pedal is in need of a broken footswitch repair, please contact me.

MXR Dyna Comp repair

Dyna Comp Repair

The Dyna Comp is possibly the most famous of the compressors used on guitar. This Dyna Comp repair was similar in nature to the ESD fix that I’ve documented elsewhere in relation to the Carbon Copy pedals. 

The issue is with the switching circuit – the FX does not switch in when the pedal is pressed.

There was a small complication in the Dyna Comp repair however – this unit uses through hole components which are now obsolete. It took a very steady hand to fit the 1mm wide body of the modern equivalent part into the massive space left by faulty component, but fortunately I’ve done this before many times in R&D work.

If you’re interested in the Dyna Comp, check out my analysis of the Behringer DC9, a clone.

UPDATE: 2017

The MXR ESD repair kit is now available for sale at www.rsdsound.co.uk. If you’re an experienced repairer and skilled with SMT repairs then you can purchase this kit. If in doubt, just post it to me and I’ll sort it for you. Note that some DynaComp are not SMT.

http://www.rsdsound.co.uk/product/mxr-carbon-copy-esd-repair-kit/

If you have a Dyna Comp repair with problems, please let me know.

Wrong power supply repair – MXR Carbon Copy Repair

wrong-power-supply-mxr-pedal-repair

Here’s another MXR carbon copy repair – this one had been damaged by the use of the wrong power supply. I’ve repaired quite a few of these Carbon Copy pedals – the older ones are prone to an ESD related fault that’s quite easily fixed. This is the first carbon copy I’ve seen since MXR implemented the ESD fix on their production line. They use the exact same methods that I’ve been using since first discussing the repairs with MXR in 2013.

In this case, the owner had mistakenly plugged the pedal into the wrong power supply. This pulled a very high current into the pedal and burned out some components. Fortunately I had the parts in stock and was quickly able to fix the pedal with only a small cost to the customer. Whilst I don’t recommend plugging the wrong power supply into a pedal, it’s rarely a death sentence!

If you’ve plugged the wrong power supply into your pedal, don’t panic. Just drop me a line!.

Line 6 Repair – Pod XT live

Line 6 Repair

Oh dear! This line 6 repair was a bit of a mess – you can see on the right hand side of the pic that the board has been burnt by some over heating rectifier diodes.

Most pedals run from a DC supply, but a lot of line 6 gear uses and AC supply. A popular reason for doing this is to allow the designers to simply create positive and negative DC power rails in the unit. They don’t just do it to confuse guitarists! The AC supply must then be rectified by diodes and filtered with caps to create a DC supply. Its these diodes that were destroyed.

Anyway, I was surprised to see that the diodes on this unit look like 1A packages when the unit is specced for 2A intake. The line 6 repair procedure was therefore to replace these with meaty 3A diodes to prevent further problems. The owner is lucky that none of the sensitive DSP and microcontrollers appeared to have been damaged as these could not have been replaced.

Due to the complex nature of the DSP kit that they use, line 6 repairs can sometimes be uneconomical – whole boards sometimes have to replaced in line 6 repairs. However this line 6 repair was completed in the first hour and was cheap for the customer. If you have a line 6 repair job for me, please get in touch and I’ll try to advise.

Myth avoidance: Pedals made with surface mount technology are not that hard to repair, though very fine pitch SMT can be harder. What is next to impossible is the replacement of DSP and MCU chips. Since I don’t have the code that was loaded onto these I can’t repair them, and so these repairs can only be done by a board replacement.

MXR Repair – Carbon Copy

MXR-Repair

This MXR repair, a Carbon Copy, was a simple fix. ESD (static) had destroyed 3 switching transistors used in the bypass circuitry. After identifying the fault I contacted MXR to find the part numbers of the damaged items. MXR are aware of the issue and recommended a modification to significantly reduce the likelihood of a repeat problem. I’ll take this moment to thank the guys at MXR/Dunlop (partic. Derek Jones) who provide excellent tech support.

UPDATE: 2016

I’ve since repaired many of these and I now keep the parts in stock ready for the next MXR repair.

As you can see on the photo on the other delay pedal repair page , this MXR uses surface mount technology (SMT). Some find this a little fiddly to repair and many repairers won’t touch it, but I actually prefer it to through hole!

UPDATE: 2017

The MXR ESD repair kit is now available for sale at www.rsdsound.co.uk. If you’re an experienced repairer and skilled with SMT repairs then you can purchase this kit. If in doubt, just post it to me and I’ll sort it for you.

http://www.rsdsound.co.uk/product/mxr-carbon-copy-esd-repair-kit/

MXR Repair – Carbon Copy

If you have a an MXR Repair or a Dunlop Repair job that needs doing please, get in touch.