Kudos to you, Stuart, for challenging yourself on this nightmare. Mesa is, and always will be 6 pounds of shit in a 5 pound box. They are so non-conducive to servicing that no one enjoys repairing them. I applaud your method to deduce the issue. The post has indeed slowed from the influx of parcels for the end of year observance. Well done as always Stuart! Enjoy the weekend, and stay safe and warm. Cheers!
Stuart, I 'd like to thank you for all the time and effort you have put into creating your most informative and very entertaining videos. Your warts and all approach is quite refreshing and helpful as I attempt to do my own amp repairs. It's encouraging to see others hit the same roadblocks as myself so as not to be discouraged. I wish a Happy Christmas to you and your family, and I hope you have a wonderful and profitable New Year! Jerry in Las Vegas
Excellent diagnosis tips, tricks and fixes there Stuart.. You're a brave man taking on a stomp box that has the mark of the beast (Mesa). Hope you have a great Christmas and a prosperous new year and you get back to us in 2024 with some more great videos.
Hey sir! You saying "not being a guitarist" is a bunch of Mesa pedal. Your demo playing on your videos is much better than what most people consider an okay player. Me included.
Hello Stuart. Another good fix. Pedals are never good fun to work on but that one is one of the hardest. Have a good Christmas and a happy new year. Take care.
Chemwik is some good braid. I have used cheap braid and put flux on it and that works really well.when run into an issue with the braid not soaking up the solder I’ve always added extra flux and it helped a lot.
A lot of issues with these old Mesa products are those old Vactrol opto-couplers. I've had many Mesa products across my bench with issues that were all tied to those opto-couplers. They are obsolete and hard to come by, It was a bad design in the first place. A cheap and dirty way to do switching operations instead of using a relay.
Hi Stuart. Just came across this. Great diagnosis and thought this might help. Bad design as no heat sinks on the regulators. Out of the case there is plenty of airflow which is why I think it took ages to show the heat related fault. Also other than the valve cover there appears to be no other ventilation. I have repaired a couple of these in the past and with the customers consent I have replaced and mounted both 12v regulators on the case side with fly leads to board so case becomes a massive heat sink! There may or may not be any where to mount them on this version though. Cheers Keith
I was thinking along the same lines, but one will have to be very careful in measuring the regulator voltages (accessible only from the underside of the board) because the whole unit turns into a such a floppy mess when it's disassembled. You'd have to prop it all up with several layers of towels so that it didn't short circuit just from trying to put your probes on the solder joints on the underside of the regulators. One slip and there'd be lots of damage....... Also I would have put heat sinks on all 3 regulators because they are doubtless generating a tremendous amount of heat and probably being run well above their ratings (since that's how Mesa Engineering rolls). Those caps are getting baked by all the heat, and that little orange cap should have been replaced.
@@carelmulder8035 , More likely you'd have to measure voltages at the top end of the resistors that feed power to the op-amps, and without a schematic in hand you'd have to use an ohmmeter to locate those. I miss the days when circuit boards were single-sided and you could easily follow traces by the eye, and there were silk screened circuit paths shown on the component side of the board so you didn't even necessarily have to look at the foils to figure out what was connected to what....PS, even with sharp probe tips I've occasionally slipped off the pin of an IC while taking voltage measurements, shorting voltage to an adjacent pin, so it's something that I avoid doing if possible, especially if the circuit board is flopping around loosely.
Hi Stuart, nice to see you're enjoying yourself with this RU-vid channel. Do you think you'd ever talk more about the economy and business again? I sometimes think "I wonder what SG would be saying about CBDCs, etc.", although I could probably guess! Anyway, good luck in whatever you do.
No I probably won't do that again now. Fun whilst it lasted though! BTw in all the years I've been doing this channel, you're the only person to recognise me!
I love Young Stuart! ( I'm bloody old !72 Christmas day!!) But yeh! being a grumpy old man ain't so bad! Never mind! Great vid as always mate, Have a Great Christmas and a happy healthy New Year! xx ( Keep these vids coming!)
Also, I noticed that the component that looks like a Regulator that's adjacent to the 7812 Regulator, looks like it has the telltale blemish that indicates it may be faulty too.
Nice job. Sometimes those things can be very difficult to repair without schematic. And even PCB polarity markings can be erratic like was in my 80's Alesis micro series rack EQ, and the polarity of two electrolytics of a regulator circuit was reversed in factory. However those caps survived reverse polarity because they were 50V caps on 12 or 15 V voltages.
It's a fantastic pedal. Nothing else does what that does. The recessed pots can't be hit with your feet so it is a great design feature. The valve cover serves a purpose. Wish I still had mine!!
The knobs seem a little large for the recess they sit in, and don't seem have clear markings that can be easily seen on stage. I'd prefer something like chicken head knobs with a point so that settings are more easily visible and repeatable. I bet those knurled metal knobs added a significant cost to the product, and were chosen to be in keeping with the industrial-chic look of the device, and not for the actual function it's supposed to serve.
Hey Stuart, interesting fix..! Robust for sure and I suppose they are somebody's dream machine,,A bit too cumbersome for me..Nice vid...Happy Xmas, by the way..Ed..uk..😃
My guess is that those 12V Regulators stop functioning correctly when they get too hot and stop producing the +/- 12V DC as a consequence, I'm surprised that Mesa/Boogie didn't add heatsinks to those two 12V Regulators since it is standard design practice to do so, I bet none of the so-called "Engineers" working for Mesa/Boogie have ever had to fault find any of their designs for their products.
Nice one there Stuart. A little different for you this time, but I do appreciate the troubleshooting tips. I've never seen one of these, but it does sound good. I wonder exactly what the tubes are doing. Are they part of the power section or just giving that tube sweetening to the sound? Merry Christmas
I'm only 24 min in, so I may have to correct this, but I would opt to get some of the little heat-sinks that fit onto the regulators, rather than just replacing them
Knowing that Mesa have a history of running componets at 20 to 50% above the maximim ratings, it would have been a good idea to add heat sinks to all 3 of those voltage regulators. There's almost no air flow inside the device, and excess heat is gonna kill those capacitors prematurely.
@@stuartukguitarampguy5830 We have slip on aluminum transistor heat sinks at work that would definitely fit. I've used them in tight spots like that in the past.
Hey Stuart, you'd think some of these armchair tech comments would be a little more intelligent. Great job as usual ..Ed ..uk😅@@stuartukguitarampguy5830
High quality solder-wick doesn't generally need extra flux because the braid is supposed to be impregnated with it, but if it's cheap braid, or it's old and oxidized, then adding a little flux is indeed very helpful.
I do have a proper desoldering tool but I often can't be bothered to fire it up for a quick component removal. The braid works pretty well most times. I'll use the desoldering station to take out an IC or similar.
@@stuartukguitarampguy5830 if there were an internal short circuit in the voltage regulator then it might be hotter than the surrounding components. But in this specific case it was difficult to know if the heat was produced by the component or the surrounding heat just made the component malfunction.
@@stuartukguitarampguy5830 , I live in the northeast US where jesus is only pronounced as 2 syllables. In the South it might be 3 syllables, but I've never heard it pronounced as 4. On your side of the pond , of course, you pronounce aluminum with 5 syllables! 😉
I'm sorry Stuart But The recess like that Because you will hit them with your foot when you change channels or preset w it a stomp. You just said you're not a guitar ist
