Chosen Solution
Hey guys, I’ve been using my Mackie CR3 monitors with my Mac with no trouble for about 2 years now. Suddenly when I turned on the computer today I realized that no audio is coming out of the monitors. The monitors are powered on (the green light surrounding the volume knob is on.) And strangely, when I connect a pair of headphones to the Aux out port in front of the active monitor, I can hear well through the headphones. Does anyone know a fix for this? Thanks in advance for your help.
I picked up a set of these from a wholesale liquidator auction site and had the same issue. I tried replacing the amp chip but no good. Finally as a last ditch effort before throwing them away, I cut pin 5 on the amp chip (TDA7265) which was the mute pin. I get sound from the speakers now, but they don’t mute when I plug in headphones, which is fine by me. Everything else works as intended it seems. Probably not the ideal fix, but it works for me.
Plug in and remove your headphones a few times really fast it sounds stupid but it will work
The real problem is sometimes further in the circuit. Like ‘forest’ was saying in another topic I fixed a couple of them by replacing only the z4 zener diode. It gets really hot during operation, and stuff just breaks: Had the same issue, caused by the heat around Z4 diode. Fixed by replacing the dead cap C74 (100u/16v) and the diode Z4 (12v 1W zener 1N4742), check maybe you need to replace more components, R2 for example. This area of the pcb is generating “mute” signal for the amp, so no wonder the trick of cutting “mute” pin of tda7265 works sometimes If you want the simple solution. you don’t have to cut the pin (messy), just cut the jumper in the red box:
To comfirm, when looking at the chip attached to the heat sink, the pin I have drawn a yellow line from in the diagram (the 3rd long pin in starting from the right hand side (at pin 1) with the heat sink behind the chip - you will notice pin 1 and pin 5 are both long pins forming a total of 6 long pins and nesting adjacent (underneath) each of these long pins are 5 smaller pins forming a total of 11 pins) is DEFINATELY the one you cut if having this no sound through the main speaker issue! It simply means the speakers won’t mute when you plug your headphones into the jack.
Please see pin 5 in the diagram below as explained above:
i have same problem on my CR3..solved by removing the R88 (1k ohm resistor) and changing with new one…cutting pin 5 of the ic chip will deactivated mute circuit and resulting popping sound when turn on/off main switch
As spraying Contact Cleaner only fixes the issue for a month or so for me, I went in with a Multimeter, and figured out how to just bypass the switch altogether. Makes your ‘selection’ permanent, but not a big deal for keeping the speakers out of the trash. I clumsily wrote my first guide ever on how to do it yourself, hope this helps others: Mackie CR3 CR4 L/R Speaker Selector Bypass Labeled ‘difficult’ because it requires soldering, but if you are comfortable with that, this is a quick and easy fix.
fwiw - for my Mackie CR3s: The two big power supply smoothing caps - the 4700uF caps, C76 & C77, were obviously bad as they were bulging. And no surprise given the heat the power supply generates, esp as it’s enclosed inside an insulated speaker box. So I replaced those; but that still didn’t fix it. I still had bad voltage readings. I then replaced the two regulator zenier diodes, Z3 & Z4. That did the trick and all is currently working fine. I’ll probably modify the powered speaker to leave the electronics outside the speaker box so the heat can better dissipate. There are ‘proper’ fixes out on the internet that involve bypassing the original power supply regulation section with LM-series voltage regulators. Those fixes will significantly reduce the heat produced, which should help with longevity. Also fwiw - on the MUTE issue re the mute pin on the TDA7265: It has been noted that inside that chip the mute function also performs a voltage safety check; so ideally you shouldn’t fix the mute issue by simply cutting that pin. The mute circuitry is voltage dependent. If the mute failure isn’t fixed by cleaning the headphone contact; then you probably have failing caps and diodes. C76 & C77 should probably just be replaced ever few years anyway as they take a beating. Replace those, then Z3 and Z4. If that doesn’t fix it, replace the capacator and diode in the mute circutry - C74 and D1. NOTE that I myself am not an electronic circut expert; I am here consolidating a bunch of research I’ve found across the internet.
With the Power remaining TURNED ON, Go ahead and remove your auxilary cable from the source of audio it is currently plugged into and quickly plug it in and out of both the aux & headphone jack on the bottom right of the Mackie Cr3 Powered speaker.
One thing to keep in mind is this speaker amp overheats regularly so unplug them cool them down and shut all switches to off and then flick your powered speaker L/R switch a few hard times it works for me now i have proper sound through both speakers 4 years it has worked everytime it must be a loose connection but that seems to kick it back in try it!
Thank you very much! Cutting pin 5 did the trick for me.
Has anyone seen this issue? very low freq hum on power on: https://youtu.be/9l2KQoYD428 looks like i have some burned components
Replace 4.7k resistor that enters pin 5 of the TDA7265, Reference R88 4.7k
can someone please help me with the cutting pin 5 issue, as the cr3xbt interior looks different to the cr3
