Re: Repairing Alesis M1 Active mk2 Monitor Speakers
ok, so this means my replaced Q1 is faulty. What would be the best way to continue? I could replace Q1 again, but my gut tells me it will break again since there is another component faulty which I still need to identify. I have a working speaker that i can cross measure stuff, but I'm just not sure where to begin...
markovitch
Member
Last Activity: 01-05-2018, 09:58 AM
Joined: 09-10-2017
Location: almere
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Re: Repairing Alesis M1 Active mk2 Monitor Speakers
thanks for the clarifying images, Q2 and Q1 give ma about a diode drop when measuring source to drain. Q1 does the same for gate to drain. Q2 gives no reading on gate to drain (reads 1).
Is the gate to drain supposed to give a diode drop? Or is Q1 defect (i did replace this one so sounds weird).
EDIT -- i read on and noticed you mentioning
This leads me to thinking Q1 got faulty again, but now to found out what caused this. Any suggestions on that?...Leave a comment:
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Re: Repairing Alesis M1 Active mk2 Monitor Speakers
Q1 gave about a diode drop measuring left leg, same goes for right leg. Q2 gives no reading with the left leg (as in, no drop), right leg does give about a diode drop.
Seems like Q2 is partially defect then right?...Leave a comment:
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Re: Repairing Alesis M1 Active mk2 Monitor Speakers
thanks for the reply, sorry for my slow replies but I'm doing this in the little spare time I have (as do most of us probably
).
I measured Q1 (was replaced by me before already), it's fine. Q2 on the other hand does not give any reading, so it looks like it's broken.
R5 and D5 are what they should be. Funny thing with R3 and 4 is that the reading seems legit, but the resistance keeps climbing if i measure for a longer amount of time. Not sure if this is my inconsistent measurement or normal behaviour...Leave a comment:
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Re: Repairing Alesis M1 Active mk2 Monitor Speakers
Ok did some measuring, counted the pins counterclockwise starting at the 'half moon' on the chip.
5 to 7 shows me 350-400 and 5 to 8 shows 650-700. I know a diode should give a drop of about 600-700, so does this means the chip is in bad shape?Leave a comment:
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Re: Repairing Alesis M1 Active mk2 Monitor Speakers
voi perkele, excuse my finnish
I could cross measure some parts with the working speaker I have, what would be a good starting point for this?Leave a comment:
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Re: Repairing Alesis M1 Active mk2 Monitor Speakers
Ah, interesting. I was having a hard time understanding the part specs and after finally getting the right components there is more to keep in mind :O
For the C8 part I ordered this one:
[url]https://www.conrad.nl/nl/elektrolytische-condensator-radiaal-bedraad-5-mm-330-f-35-v-20-o-x-h-10-mm-x-16-mm-europe-chemicon-eky-350ell331mj-1505587.html[/url]
It doesn't state anything about ESR values, funny since they seem important.
Do I understand correctly that this part might be 'not good enough'?...Leave a comment:
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Re: Repairing Alesis M1 Active mk2 Monitor Speakers
No, i replaced that one earlier as it being one of the most common problems.
I did measure it before and matched it to the still working speaker of mine, the values were the same....Leave a comment:
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Re: Repairing Alesis M1 Active mk2 Monitor Speakers
I've done a few measurements and between 5 and 7 I get 0.77 V roughly.
Not sure if this is bad or good, if bad what do I measure next?...Leave a comment:
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Re: Repairing Alesis M1 Active mk2 Monitor Speakers
Yes you're correct in that this approach isn't the most efficient. I just thought i'd give it a shot since it seems a common problem with these speakers. On my 2nd replacement round I did actually measure components and determined they were broken
I will measure the voltage soon, and see if I can notice anything.Leave a comment:
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Re: Repairing Alesis M1 Active mk2 Monitor Speakers
Hey guys,
found this topic after one of my speakers blew out my fuses and decide to have a go at fixing it.
I've replaced the diodes (d1-4) the big black caps and C8, c35 and the fuse after finding a youtube repair video. This wasn't enough as it then burnt up r15 and rt1 mosfet exploded :/
I've replaced these, the diodes again, and Q1 as well after using a multimeter to reference some parts with the still working speakerboard.
Now nothing happens, power on doesn't blow...Leave a comment:
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