Re: Repairing Alesis M1 Active mk2 Monitor Speakers
Updates...
I was supposed to work some more on this Sunday but She Who Must Be Obeyed decided she wanted to paint the kitchen, so there's that...
The top of C6 capacitor feels like a firm bubble, meaning I can push it down and it springs back up.
The noise is loud enough to hear, especially when turning the unit off. Not sure if you can hear the sustained tone in the video but you can most definitely hear it when it turns off... [url]https://photos.app.goo.gl/HboTvjY7sfEbCBpJ6[/url]...
jgulyas
Member
Last Activity: 12-15-2023, 07:04 AM
Joined: 01-09-2023
Location: Roanoke, VA
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Re: Repairing Alesis M1 Active mk2 Monitor Speakers
Well... mild success I guess... the unit powered on and the blue LED is no longer blinking... but now it's emitting simultaneous tones 13.5kHz and 6.3kHz.
Any ideas with that one??Leave a comment:
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Re: Repairing Alesis M1 Active mk2 Monitor Speakers
Regarding C8 and its legs, I put it over there to get it away from the hot resistor. How do I get it away from the heat of that without having long legs?
Someone needs to show me what you mean about adding a light for testing. All I can see in my head is a standard household lightbulb attached to this thing somewhere.
Jackson capacitor??...Leave a comment:
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Re: Repairing Alesis M1 Active mk2 Monitor Speakers
Welp... it sure ain't pretty... It really felt like the holes were too big for the solder to pool at the bottom of the lead on C8.
I hope L4 and D14 look alright?
John...Leave a comment:
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Re: Repairing Alesis M1 Active mk2 Monitor Speakers
Alright. I understand about running jumpers to connect the component to its proper trace... It looks like in this instance I can just solder one of each components' legs to those little bare sections (outlined in red) on the edge of the hole?...Leave a comment:
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Re: Repairing Alesis M1 Active mk2 Monitor Speakers
Well, before I get into testing diodes and such, is the board toast? As you can see, there's nothing remaining of the two holes for L4 and D14....Leave a comment:
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Re: Repairing Alesis M1 Active mk2 Monitor Speakers
Ok, sorry for the delay, I couldn't do anything until I got the bits and pieces...
I have a new multimeter so now you guys can tell how to do what it is I need to do, if I even can with this one.
Next, notice the size difference in the old inductor and the new one! As far as glue, do you think I need it since the new one has that little base on it? And which kind of glue, hot melt?
Grinding down the cooked part of the PCB... what to use... a Dremel? Honestly doing that...Leave a comment:
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Re: Repairing Alesis M1 Active mk2 Monitor Speakers
i think what you saw was a shadow. Here's another picture with better light on the area......Leave a comment:
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Re: Repairing Alesis M1 Active mk2 Monitor Speakers
OK... so here's what the board looks like without L4 and D14...
And here's the inductor...
To me, Q3, Q4, C15, and D9 all look fine.
Also, in the section with C8 that I've already taken out, C6 is rounded/puffy at the top while C7 is flat. The guy at the pro audio place said he'd replace both of those as well. Both of those have the yellow (now brown) glue on them as well....Leave a comment:
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Re: Repairing Alesis M1 Active mk2 Monitor Speakers
I *had* a very nice multimeter that I carried with me when I was in the Navy and running audio all over the world... but I've lost it. I'm looking at getting another but don't want to break the bank on one. Anything specific I should be looking for as far as functionality?
Done.
Can I measure inductance on a multimeter, and what should it read if I can, 25uH I'm guessing?
Should I just take all the burn looking pieces off...Leave a comment:
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Re: Repairing Alesis M1 Active mk2 Monitor Speakers
Ok, so I took some time with some of the IPA you guys are talking about and cleaned up the board. I had a Pilsner by my side as I prefer that over IPA. but that's beside the point.
Still think it's fixable? The inductor L4 looks like toast to me, but you guys know a ton more than I do!
Oh, and I have no idea what the UC3844 IC even is......Leave a comment:
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Re: Repairing Alesis M1 Active mk2 Monitor Speakers
Thanks for the response and input! Over the last couple days I've been scouring the web for replacement parts and am pretty sure I'm going to need to replace that inductor at L4. I found this on mouser.com ([url]https://www.mouser.com/ProductDetail/Pulse-Electronics/PE-54041NL?qs=5htIM77pc3v7D8GrAAAO0g%3D%3D[/url]) and am wondering if this will work as a replacement? The Alesis tech manual for these says it's an Inductor Resonant 25uH 3A. The original is just the loop help in place by the exploded goop and the one...Leave a comment:
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Re: Repairing Alesis M1 Active mk2 Monitor Speakers
Here are the pics that I forgot......Leave a comment:
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Re: Repairing Alesis M1 Active mk2 Monitor Speakers
Hi Folks,
Just joined and have been reading up on how to repair these things. I have an issue that I don't think has been brought up yet. I bought a set of these monitors knowing that one of them had the issue with the blinking light so I've been prepared to do a little bit of work to have a great set of monitors. When I took the board out I noticed on mine that it looks like there was an explosion at L4.
Is this fixable??Leave a comment:
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