Fixing a Mesa Boogie Triaxis


This fix involves messing with a tube preamp running high voltage that can kill you. If you choose this path, do it at your own risk, I can’t be blamed!

Mode Erreur

A colleague I’m sometimes playing the guitar with came to me the other night with his dying Mesa Boogie Triaxis. Apparently this famous preamp works fine for 15 minutes, before falling into error mode, displaying his inner pain on the front panel display through the mysterious message “.3″ which, according to the doc, stands for “Err”.

A quick search on the net shows that this is quite a common issue, but I couldn’t find a concrete solution that doesn’t involve a $400 Mesa Boogie factory return.

Come on, a 90’s rack preamp should be easy to open and fix !

Here it is, laying on the surgery table, with all the care and concern of a tubes stuff guts (high voltage, afro haircut, death, and so on).

Triaxis Guts

Without surprise, it’s designed to be opened and tweaked, so a first diagnosis is easy to get. But let’s be honest, a full disassembly will be a PITA. So let’s hope it won’t come to this.

Both symptoms and Internet comments (microcontroler failure, not serviceable) made me want to blame the digital part and not the analog part, so I focus on this.

At first sight, everything’s fine. Some tantalum caps that could be on their aging days, but nothing pops up. Let’s look under this Faraday cage that must protect microcontrolers from electric noise.

Got the micro?

As expected, here are the Triaxis chip and some Z80, that I hope are fine.

Z80 and Cie

But having a closer look, there’s this C18 tatalum cap leaking, and IC11 dressed as a smoked rib. With a more chemical smell. That depends on the restaurant though.

IMG_0667 2


IC11 is a TL7705ACP, a supply-voltage supervisor, making sure that voltage is as expected before turning on other part of the circuit. If it goes beyond limits, it can be used to shuts things off or trigger errors. And the voltage of reference is decoupled by C18, the damaged capacitor. It’s thus very likely to trigger errors after a short period of time, which could explain the message on the front panel of the Triaxis!

Let’s order a new TL7705ACP and some 100 nF tantalum cap, even though a ceramic could do the job.

A few days later, parts arrived, and I call my colleague. Yeah, 40 minutes before my train, plenty enough of time!

I start by removing damaged parts. Simplest way to do it in my experience is to cut every pin, and then unsolder them one by one. Then I clean the leaks of cap juice and carbonized dusts.


This part of the board is obviously burnt on several areas, so I don’t want to struggle and solder new parts directly. Actually I can’t because it’s hard to solder and can be damaged further. Pin 6 of IC11 in particular is just carbon at this stage, so I’ll connect it elsewhere on the circuit.

I check with a multimeter how everything is connected (GND, VCC, VREF, RESET…) and try to figure out how the part is used, based on the circuit reference from the datasheet. Again, I’m a little confused by how the RESET pin of IC11 is used, directly connected to ground. As the circuit is damaged here, I cross check my multimeter result with a visual inspection of the bottom layer of the board: that’s a match, so I’ll reconnect it like this, and will trust Mesa Boogie’s engineers (but if it was me I would have put a 10k resistor).


Visually, it’s ugly. Probably one of my worst fix, but that was fast and it avoided a full board disassembly. Anyway I can’t see any influence on sound or reliability, so who cares.

A few other checks with my trustworthy multimeter, and I plug the beast.

No smelly blue smoke, no heat, and no errors on display anymore!


A $2 fix instead of $400 :) Pretty sick!

The beast has been running fine for 2 weeks, and my colleague is happy!

Posted in Crafting, DIY, Non classé | Tagged , , , , | Leave a comment

A painless Magic Keyboard?

iErgoKeyboard - 1 iErgoKeyboard - 4

I usually spend around 14 h a day in front of a computer. At this rate, a bad posture is merciless and pain appears quickly. As a consequence, I took a dive into the world of ergonomics years ago, and I’m always looking for this comfy peripheral that would associate geeking and peace of mind.

For long days at work, I love the Microsoft Ergonomic Keyboard 4000, and I usually went back to the Apple wired keyboard in the evening, once back home. Alternating posture is a good way to release muscles.

But when I crossed the Atlantic ocean, and went full Apple, I was disappointed when I started looking for an ergonomic keyboard, Mac compatible, with French layout, and available in the USA. The best I found is a French layout Magic Keyboard, but it’s still an abomination, ergonomically speaking.

First, I wanted to mess with a Dremel, and giving it a V shape… But a negative slope, widely approved by ergonomic professionals, was easier and less definitive.

I launched my CAD software one more time, to create a pair of accessories to be clipped on the Apple Magic Keyboard, instantaneously featured with a relieving negative slope of -6,8°.

2 weeks later, the result was shipped to my mailbox. And the first days of use were delightful!

iErgoKeyboard - 1 (1)

It’s not worthy of the true ergonomics keyboard, obviously. But it’s always good to take and your wrist will be spared and ready for breathless foosball games.

iErgoKeyboard - 5

iErgoKeyboard - 6

So if you have a Magic keyboard you want to use for a long time, have a look at those cute accessories on my Shapeways shop.

And as in my opinion, everybody should be healthy and have access to ergonomic peripherals, the Brimbelle Lab iErgo Keyboards are under OSHW (Open Source Hardware) licence, and files can be downloaded here, so that you can modify or print them yourself.

Posted in 3D-Printing, Brimbelle Lab, Non classé | Tagged , , , | Leave a comment

Pimp my cable

You fear people’s feet passing dangerously close to your power cable crossing the alley of the Starbucks to charge your brand new laptop? You got a 42 ports USB hub, with every single one busy, and you unplugged the very hard drive on which you were cut-pasting a back up with a gazillion subfolder and tiny files?



I might have the solution to your troubles.

I’ve thought about paint (cracks and scratch gonna happen), electrician tape (sticky cable collecting all the dust and dirt existing on Earth, yummy…), but I eventually imagined and created these little clips to be 3D printed, in all the colors you might think of.


Do yourself a favor and treat yourself with these little accessories, sold by pack of 30, on my Shapeways shopin 3.0mm (for cable from 3.0 to 3.7mm, i.e. 0.1181″ to 0.1457″) or in 3.5mm (for cable from 3.5 à 4.4mm, i.e. 0.1378″ to 0.1732″).

iPhone cable coming soon…


Plus you’re sure now that nobody will stole your charger “inadvertently”!

Posted in 3D-Printing, Brimbelle Lab | Tagged , | Leave a comment

New York – 1

More on my Instagram!

9-11 MemorialTrump Tower


Flatiron Building


DUMBONorthpole Bar

Brooklyn Bridge

Brooklyn Museum

Chamber Street Subway Station

Posted in Non classé, Photography | Tagged , , , | Leave a comment

3D printing rox!

I have a sortof distorted sense of direction, causing my bicycle trips to be often much longer than originally planned. That’s why I recently bought a Sigma Rox 10.0 GPS, and I obviously took it when I moved to New York.

But once there, I couldn’t find the mounting parts I used to order in France. Actually the only one I found doesn’t fit the 27 mm handlebar of my old singlespeed, and is kinda expensive (20$).

I could have easily made something with usual tools, but I didn’t really brought my workshop with me across the Atlantic and thus, I thought of 3D-printing.

After one hour with my favorite software, and a few hesitations taking measurements without a caliper, here’s the result !

First rendering

As far as the printing material is concerned, a standard ABS or Nylon is perfect. There’s no particular weakness to be concerned about, except for water resistance.

Wishing my shipment to be received quickly, I made it printed by Shapeways. But I didn’t account on U.S. Postal taking five days to achieve a 10 km trip (:


With GPS in place.

White plastic with polish finition.

Purple plastic with polish finition.

2 prototypes were printed.

This part allows to mount the GPS perpendicularly or in parallel to the bar (handlebar or stem), through 2 ziplocks (under 5 mm width or 3/16 inches). For more exotic kinds of mounting, you can also use the two holes which fit two M2 screws with countersunk heads.

With ziplocks in place

Here is the result, mounted on my bike!

Mounted on the bike...

... and with a GPS on top of it!

I’ve made a bunch of changes on the printed part, which improves the ziplocks mount when used on wider bars, such as a-head stems.

Final part

The .stl file is available here if you have a 3D-printer, or directly through my Shapeways shop :

I place this file under Open Source Hardware licensing. However, if you don’t feel like ordering through my Shapeways shop, and you download and print it on your own, your support through a nice comment or a Paypal donation would be utterly appreciated!

Posted in 3D-Printing, DIY | Tagged , , , , , | Leave a comment










Posted in Non classé, Photography | Tagged | Leave a comment

Lost in translation

I love the French language (although I happen to bully it from time to time).

For now, I was convinced to write this blog in my native language only, hopping to help narrowing the gap french has with other languages on the web, with its 8th position (sources: Wikipedia)

But letting my laziness beliefs win is reaching only 3% of the web users. And I hope that this website will eventually interest 3-4 readers out there.

So, this is the English version of this blog! With probably plenty of language atrocities, so feel free to contribute making the web a better place by sending me an email with corrections :).

Articles will be translated progressively, newer first. If you can’t stand waiting for it, may I suggest you to click on the French version, top of the page, right, with this little blue-white-red flag?


Posted in Non classé | Leave a comment

Maté el ordenador…

Well, I didn’t. That was only to introduce the murder’s weapon : Yerba Mate. This is some highly conductive beverage that, oddly enough, make serious damage when split over the keyboard of an Asus X53S laptop.

The murder's weapon.

Emergency procedure: turns everything off, unplug the battery and power outlet, and let any liquid flows out and dry for a few days. Asian technic: put the device in a closed bag with rice, which will absorb humidity.

If on the contrary you are the kind of guy to carry on with your thesis manuscript whatsoever, even if your keyboard misbehaves and despite pyrotechnic effects coming from the inside of your computer, here is a way to bring your laptop back to life.

DISCLAIMER : Fiddling stuff randomly is the best way to learn, but also to hurt yourself. I can’t be held responsible for any injury, death, or destruction that might occur following this article. Be careful, unplug power supplies, and never let a hacked device without supervision unless you are sure of your hack.

Legal aspects being detailed, let’s hack!

In a nutshell: the motherboard has been seriously damped in maté. Careful cleaning done, two transistors have burst (MTB20N03AQ8) and another one (IT8572E) with pins oxidized by the beverage.

First ones are not available in France, but there are equivalents largely supplied. (Farnell, Mouser, RS…).

The second one is much more difficult to find. So let’s assume some hot-air rework will be enough.

I’ve considered buying a new motherboard from Aliexpress or eBay, but it turns out kind of expensive, whereas repairing my current motherboard seemed a reasonable challenge, if the diagnostic was correct. And if not, I can afford buying two transistors for nothing, and pick a new mother board later.

During repair, I noticed that a resistance close to one of the transistors I was changing looked very bad. Ohmeter spoked: infinite resistance, whereas the other transistor presented a similar design with a resistor of 100 kohms. This design is familiar: it’s a low-pass filter. Let’s put the same value on this side and everything happen, well, happens.

Desoldering it, the electric path went along with it, probably damaged by the short. Fortunately, a via was nearby, which also let me replace the 0402-sized resistor by a bigger one.

Putting everything back together, pushing the big button.


And here it is, ready for duty! How many Windows update in six months? :D

And here it is, ready for duty! How many Windows updates in six months? :D

Everything starts fine. The keyboard appears to be dead too. But it’s 15$ on eBay so this is no big deal.

Final word: don’t throw your electronic devices… They might be repaired. If you don’t think you can handle it, have a look anyway, go to a makerspace, or give it for free to someone who can fix it. One less piece of garbage contaminating the planet!


The murder’s weapon.

Posted in DIY, Non classé | Tagged , , , , , , | Leave a comment


Each year, when Christmas come, I know that I won’t sleep much because of hand-made present I like to offer.


This year, I will focus on mom’s present. She is a gilder, at the Atelier Or et Patine (click!), and she happens to need some chisels, since her current ones were made in China and about to break.

The perfect opportunity for me to work with wood, steel and leather, my favorite materials!

The fact that I had to make several chisels on the same model made me design some specific tools, especially a basic lathe, from stuff picked across my workshop.


Here is the result, a leather toolbag containing 6 chisels with wood handles and XC75 steel blades (one forged).



As usual, the fabrication process is detailed in the gallery below!


Posted in Crafting, DIY | Leave a comment


Meanwhile in the sky, three planets are aligned…

Conjonction1 Conjonction2

That’s not everyday you can see both Jupiter and Venus in the eyepiece of a telescope!

Posted in Astronomy, Photography | Tagged , , | Leave a comment