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Old 05-09-2020, 08:20 AM   #61
UserXP
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Default Re: Mackie CR4 monitors

Quote:
Originally Posted by Xebozone View Post
Yes please. That is what I purchased (and what the article I mentioned suggests making). Would like to know how to wire it all in too. My speakers are collecting dust
Hi. I received the module and installed it, works very promising. I will put additional info with images soon. :-)
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Old 05-09-2020, 11:13 AM   #62
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Default Re: Mackie CR4 monitors

Guys, I just want to add an update to the problem regarding the overheating +/-12 regulator on this PCB. I ordered and finally received the dual voltage regulator module based on LM7x12 parts (after 29 days of delivery time). I ordered two of these for $6 and they seem to be built quite sturdy. Both positive and negative rails have an input and output filter capacitor rated at 35V220uF. The two red LED indicators are SMD parts, and the PCB looks clean and quality soldered.

I installed one of the modules into the powered speaker. The red light from the LED indicators does not bleed through any opening on the front side of the speaker. Of course, the procedure may or may not apply to your set of speakers. Should you try to do any of this, the responsibility falls entirely on you.

Items required (in my case anyway):

1 X LM7x12 1V dual voltage regulator module
1 X M3 stand-off with one end bolt-threaded (I only had a 10mm one)
1 X M3 screw (I used one with an integrated washer and a spring-washer)
5 X pieces of wire (I used those from and old PSU: three for input and two for output)

Now, I have included the pictures of the module and the schematics. They are not the clearest as this is the first time I have done something like this and I used the image previously mentioned in the German author's post. But at least it's something.

The module has an input connector, which needs two +/- AC lines and a ground line to work. The ground on the input side simply passes to the output GND connector, which is why only the input GND wire is required. There is no need to mount the GND wire on the output end.
Also, R1, R2, Z3 and Z4 components need to be removed from the speaker's PCB. Clear their holes of solder as wires can then be threaded through the PCB and soldered on the other side.

1) Now, the AC inputs on the module are to be connected to the incoming voltage points on the PCB (+ and - 20 V in the image), where the pins of the resistor used to be soldered. You can connect those points to the AC input on the module any way you like because the module includes a rectifier and allows both AC and DC input, so it will sort out the rails as necessary.

2) I connected the GND wire to the point where a zener diode used to be soldered, as this point is the actual GND rail on the speaker's PCB.
I used a black wire for the GND, and orange wires for each of the AC input lines.

So, the wires connected to the speaker's board, going from the left to the right, are Orange (+), Orange (-), Black (GND).

3) The module dynamically outputs only 12V of the incoming voltage. These are the rails that we need to connect to the speaker’s PCB where zener+resistor combo used to output the 12V (take a look at the included photo). The output connector of the module is connected to the second point of R1 and R2 respectively. Now, here you must not make a connection wrongly. The positive goes to the +12 marking on the PCB, and the negative goes to the -12V on the PCB.
I used a black wire for the negative, and a red wire for the positive output.

So, the wires connected to the speaker's board, going from the left to the right, are Red (+12V), Black (-12V).

Now for the mounting: I removed one of the screws that mounts the heatsink to the metal holder on the PCB. I used the stand-off as a screw to re-fasten the heatsink mount, and then mounted the module onto the stand-off. I didn't remove the heatsink to drill another hole because it would require to remove the amplifier and there was no need to do so. One screw with a spring-washer is all that it took to fasten the module sufficiently, so now it kind of floats 10mm above the heatsink.

The clearance between the magnet of the 4" driver and the back plate is 12cm. When the module is mounted like in the photo, protruding slightly toward the driver, the overall length is 10cm, which leaves 2cm of clearance for the wires inside the speaker's casing - more than enough. So nothing is hitting or compressing anything.

Please take a look at he included photos and give me your thoughts on this. Hopefully, this can help others in repairing their Mackies. I don't know why the company chose to use zeners and resistors, especially if they get hot enough to burn the PCB an potentially cause fire. A 3$ part really wouldn't increase the price to much. Unless planned obsolescence was into effect.
Attached Images
File Type: png LM7X12 Module 1.png (434.7 KB, 16 views)
File Type: jpg 20200509_150100.jpg (743.3 KB, 14 views)
File Type: jpg 20200509_134700.jpg (1.12 MB, 19 views)
File Type: jpg 20200509_134715.jpg (1.10 MB, 21 views)
File Type: jpg 20200509_141126.jpg (609.9 KB, 17 views)
File Type: jpg 20200509_141142.jpg (696.0 KB, 18 views)
File Type: jpg LM7X12 Module connections.jpg (251.9 KB, 21 views)
File Type: jpg 20200509_141416.jpg (1.06 MB, 17 views)
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Old 05-25-2020, 11:53 AM   #63
nings
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Default Re: Mackie CR4 monitors

Thank you UserXP

Same HP and same problem but not opened for the moment probably burned too.. never understand manufacturer to put noname cap and design bad pcb we should use 24/24h 7/7d just for return under warranty each time

Are you happy about the result ? No more heat ?

What about Z2 (?) the diode you removed here https://www.badcaps.net/forum/showpo...2&postcount=17
I view this diode exploded on one picture of another customer no overheat problem there with the dual voltage regulator ?


I order this DIY part on Banggood because want try a backside mount of both LM to put them directly on the big radiator with a heat transfer pad for isolate ground.
(Link if someone interested : DIY LM7812 LM7912

Thank you for your time and sharing all information

Last edited by nings; 05-25-2020 at 12:47 PM..
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Old 05-29-2020, 12:31 PM   #64
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Default Re: Mackie CR4 monitors

Quote:
Originally Posted by nings View Post
Thank you UserXP

Same HP and same problem but not opened for the moment probably burned too.. never understand manufacturer to put noname cap and design bad pcb we should use 24/24h 7/7d just for return under warranty each time

Are you happy about the result ? No more heat ?
I'd asked myself the very same question, so I had to reopen the powered speaker while it was on for over two hours just to inspect the inside situation. The results are that the PCB no longer becomes hot at that R1/R2 area. The regulator module itself works quite cool, its heatsinks were barely mild to the touch and I think they actually warmed up to the inside temperature of the powered speaker, which would rise after a prolonged use due to the transformer. But the PCB itself no longer felt hot to the touch in the designated area. Of course, mounting the power supply externally would reduce the inner temeprature drastically. I haven't done that (yet) so I suspect some more of the smaller caps may eventually fail due to the heat. But at least (hopefully), nothing else will burn.

Quote:
Originally Posted by nings View Post
What about Z2 (?) the diode you removed here https://www.badcaps.net/forum/showpo...2&postcount=17
I view this diode exploded on one picture of another customer no overheat problem there with the dual voltage regulator ?
That broken diode, in my case, was D1, a regular diode, which was rusted and broken. I replaced it with the same type, which is 1N4148. I suspect it was covered in some acid-based soldering flux, which ate the metal away and caused the diode to break.

Quote:
Originally Posted by nings View Post
I order this DIY part on Banggood because want try a backside mount of both LM to put them directly on the big radiator with a heat transfer pad for isolate ground.
(Link if someone interested : DIY LM7812 LM7912
Yes, that could work, just make sure you use pads plastic washers for the screws to completely isolate the LM regulator from the heatsink (if you have a broken PSU, it is a great source of isolation pads, plastic washers and designated mounting screws). I also considered ordering a DIY version of this module as additional bridge rectifier or LED indicators wouldn't be needed, and the wires could be soldered directly onto to module's PCB - but I opted out for the completed one as it was actually cheaper. Seeing how little heat the module produces, I believe it will last long with its preinstalled heatsinks. So I opted not to drill aditional holes into the amplifier's heatsink. I am quite happy with how the mount came out as it aurely won't be touched or moved by anything inside, it stays quite firm on only one screw with a spring-washer. And most importanly, the speakers work great, no more cut-outs, hissing or crackling sounds. I now also turn them off using a back switch when they are not in use.

Quote:
Originally Posted by nings View Post
Thank you for your time and sharing all information
You're welcome. Hopefully, this info will help other people having similar issues, I guess sharing information and findings is the main point of this entire forum.
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Old 07-06-2020, 05:30 PM   #65
willstatus
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Default Re: Mackie CR4 monitors

Quote:
Originally Posted by UserXP View Post
Guys, I just want to add an update to the problem regarding the overheating +/-12 regulator on this PCB. I ordered and finally received the dual voltage regulator module based on LM7x12 parts (after 29 days of delivery time). I ordered two of these for $6 and they seem to be built quite sturdy. Both positive and negative rails have an input and output filter capacitor rated at 35V220uF. The two red LED indicators are SMD parts, and the PCB looks clean and quality soldered.

I installed one of the modules into the powered speaker. The red light from the LED indicators does not bleed through any opening on the front side of the speaker. Of course, the procedure may or may not apply to your set of speakers. Should you try to do any of this, the responsibility falls entirely on you.

Items required (in my case anyway):

1 X LM7x12 1V dual voltage regulator module
1 X M3 stand-off with one end bolt-threaded (I only had a 10mm one)
1 X M3 screw (I used one with an integrated washer and a spring-washer)
5 X pieces of wire (I used those from and old PSU: three for input and two for output)

Now, I have included the pictures of the module and the schematics. They are not the clearest as this is the first time I have done something like this and I used the image previously mentioned in the German author's post. But at least it's something.

The module has an input connector, which needs two +/- AC lines and a ground line to work. The ground on the input side simply passes to the output GND connector, which is why only the input GND wire is required. There is no need to mount the GND wire on the output end.
Also, R1, R2, Z3 and Z4 components need to be removed from the speaker's PCB. Clear their holes of solder as wires can then be threaded through the PCB and soldered on the other side.

1) Now, the AC inputs on the module are to be connected to the incoming voltage points on the PCB (+ and - 20 V in the image), where the pins of the resistor used to be soldered. You can connect those points to the AC input on the module any way you like because the module includes a rectifier and allows both AC and DC input, so it will sort out the rails as necessary.

2) I connected the GND wire to the point where a zener diode used to be soldered, as this point is the actual GND rail on the speaker's PCB.
I used a black wire for the GND, and orange wires for each of the AC input lines.

So, the wires connected to the speaker's board, going from the left to the right, are Orange (+), Orange (-), Black (GND).

3) The module dynamically outputs only 12V of the incoming voltage. These are the rails that we need to connect to the speaker’s PCB where zener+resistor combo used to output the 12V (take a look at the included photo). The output connector of the module is connected to the second point of R1 and R2 respectively. Now, here you must not make a connection wrongly. The positive goes to the +12 marking on the PCB, and the negative goes to the -12V on the PCB.
I used a black wire for the negative, and a red wire for the positive output.

So, the wires connected to the speaker's board, going from the left to the right, are Red (+12V), Black (-12V).

Now for the mounting: I removed one of the screws that mounts the heatsink to the metal holder on the PCB. I used the stand-off as a screw to re-fasten the heatsink mount, and then mounted the module onto the stand-off. I didn't remove the heatsink to drill another hole because it would require to remove the amplifier and there was no need to do so. One screw with a spring-washer is all that it took to fasten the module sufficiently, so now it kind of floats 10mm above the heatsink.

The clearance between the magnet of the 4" driver and the back plate is 12cm. When the module is mounted like in the photo, protruding slightly toward the driver, the overall length is 10cm, which leaves 2cm of clearance for the wires inside the speaker's casing - more than enough. So nothing is hitting or compressing anything.

Please take a look at he included photos and give me your thoughts on this. Hopefully, this can help others in repairing their Mackies. I don't know why the company chose to use zeners and resistors, especially if they get hot enough to burn the PCB an potentially cause fire. A 3$ part really wouldn't increase the price to much. Unless planned obsolescence was into effect.
I stumbled upon the same German instructions and outside of doing my own minor soldering here and there, my only electronic circuitry experience was my high school electronics class 2 decades ago.

While the Germans instructions were certainly vague, I felt that they gave you just enough info if you were willing to learn. That said, I stumbled across this forum and your solution is much more preferable. It also confirmed my theory of how the wiring should be. Thanks so much for sharing. I've been obsessing over this the past week and my speakers have been out for roughly a month now.
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Old 07-06-2020, 05:32 PM   #66
willstatus
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Default Re: Mackie CR4 monitors

On that note, I was not willing to wait for the shipment from China. I saw the DIY kit and that seemed reasonable as well. To my surprise, I was able to find the unit on Amazon that has Prime delivery.

https://www.amazon.com/KNACRO-Voltag...237700549&th=1
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Old 07-21-2020, 02:06 AM   #67
UserXP
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Default Re: Mackie CR4 monitors

Quote:
Originally Posted by willstatus View Post
On that note, I was not willing to wait for the shipment from China. I saw the DIY kit and that seemed reasonable as well. To my surprise, I was able to find the unit on Amazon that has Prime delivery.

https://www.amazon.com/KNACRO-Voltag...237700549&th=1
That's great! I'm glad you found this post informative and useful. Several months have passed since the repair and my speakers are still alive and kicking!
Also make sure you check the caps on the main PCB as some may have failed due to the extreeme heat the original voltage regulating components produced.
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Old 08-01-2020, 01:14 AM   #68
nings
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Default Re: Mackie CR4 monitors

Just two new pictures if can help someone other with the rear side


D1 => Added a second diode for reduce a little heat because already view one D1 diode burned
C80,C81,C74,C37,C38,C39 => these capacitors have high ESR so replace all just for be safe


Sorry, I didn't take pictures afterwards but I had to make a hole in the radiator to put a screw and then add thermal paste to make contact with LM and the radiator.


The temperature has gone down and no more problems since
Attached Images
File Type: jpg MackieRepair1.jpg (1.24 MB, 3 views)
File Type: jpg MackieRepairRear1.jpg (1.35 MB, 3 views)
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