Question about Alesis M1-Active MkII Main / Stereo Speaker

Open Question

Alesis M1 Active 620 - Power supply broke down

Hi,
I have a pair of speakers Alesis M1 Active 620 and one time when i plug the power cord i listened a "clap" inside the speaker and it didn't work since there. I opened the speaker and after test the power supply it didn't had power on the output. I changed two transistors FET (IRF 840), two resistores of 39Kohm 2W and one zenner 20Volts (1N4747). It still not working! I think that the circuitry of oscilator is not working because i opened the other speaker which is good and on the same terminals of the same transistors IRF 840 the good speaker has an oscillating signal!

I don't know what can I do, can anyone help me? Where can I buy a new power supply board for replace this???

Please help me, I need the speakers for work!


Thanks all a lot, best regards.
Pedro Madeira, from Portugal (email: djholtz@sapo.pt)

Posted by on

6 Suggested Answers

  • 15 Answers

SOURCE: Alesis M1 Active Mk2 Speaker won't Power Up

Hi, This is usually the Capacitor C8 on the powerboard it usually bulges and pops, its becuase its right next to a resistor which gets very hot and sometimes puts the capacitor into meltdown, yours might have gone past that stage but this is worth a look; http://www.neufeld.newton.ks.us/electronics/?p=232

Hope this helps

Cheers

Steve

Posted on Jun 02, 2009

r_ic7
  • 13 Answers

SOURCE: Fried Woofer

The problem are worsen that before. It is wisely to replace both left and right amplifier
IC, but make ensure that the power supply feed a good amount of voltage to amplifier,
Also a strong good signal. Be sure to measure it.

r_ic7

Posted on Nov 29, 2008

  • 1 Answer

SOURCE: Alesis M1 ACTIVE MONITOR amp circuitry board is ticking

Had the blue light flicker of death. Fixed this issue with a 330uF 35V cap. Sounds just fabulous now. I did get the cap out of the radiant spell of the resistor utilizing the longer leads and insulator for the leads. I had 2 months left in my warranty but figured paying for shipping to Alesis and at least 2 weeks wait just didn't compare to the $2 I spent with a local electronics shop.
Downtime=<2 hours.
Kudos folks. I've been unemployed for 6 months after a layoff and was really bummed until I found this site.

Posted on Mar 13, 2009

  • 15 Answers

SOURCE: alesis 620 m1 active studio monitors sound cutting out

It could be a power problem, unless you have blown the driver ?, carefully pull out the power supply board, and look to see if anything looks melted, burned, or capacitors popped etc. Be carefull though as I do not want to be responsible if you get an electric shock, etc. preferably look and dont touch, just use common sense ;)

Posted on Jun 02, 2009

  • 1 Answer

SOURCE: my alesis m1 active 620 monitors blue lite keeps

Thanks for following up...I took it to get fixed..$150.00 later it works..

Posted on Oct 08, 2009

  • 71 Answers

SOURCE: Alesis M1 Active MKII Don't get power / Blue light is off

Sure they don't have power? Light breaks all the time on those things. If no power still, open it up and find out if there are any loose connections from the power leads. Bad power cable?

Posted on Mar 16, 2010

Add Your Answer

Uploading: 0%

my-video-file.mp4

Complete. Click "Add" to insert your video. Add

×

Loading...
Loading...

Related Questions:

1 Answer

Alesis 620 M1 active no power no light


You just fix the power supply and Brige and check the transformer

May 18, 2012 | Alesis M1-Active MkII Main / Stereo...

1 Answer

Alesis m1 active 520 when powered up the blue indicator light turns red with no input in it.


I I have the same problem. I do not see any visible damage with the power supply and am assuming it's somewhere else. I am talking to Alesis but don't yet know what I'll end up having to do. Have you solved the issue?

Sep 29, 2011 | Alesis M1-Active MkII Main / Stereo...

1 Answer

Alesis M1 Active MKII Don't get power / Blue light is off


Sure they don't have power? Light breaks all the time on those things. If no power still, open it up and find out if there are any loose connections from the power leads. Bad power cable?

Mar 16, 2010 | Alesis M1-Active MkII Main / Stereo...

1 Answer

My alesis m1 active 620 monitors blue lite keeps blinking and duz not work


Thanks for following up...I took it to get fixed..$150.00 later it works..

Oct 04, 2009 | Alesis M1-Active MkII Main / Stereo...

1 Answer

Alesis M1 Active Mk2 Speaker won't Power Up


Hi, This is usually the Capacitor C8 on the powerboard it usually bulges and pops, its becuase its right next to a resistor which gets very hot and sometimes puts the capacitor into meltdown, yours might have gone past that stage but this is worth a look; http://www.neufeld.newton.ks.us/electronics/?p=232

Hope this helps

Cheers

Steve

Apr 14, 2009 | Alesis M1-Active MkII Main / Stereo...

1 Answer

Alesis m1 mk2 active emits low pitch hum and does not work


You need to take a closer look really, see if anything on the power supply board inside has melted, burned, popped, etc.

Mar 13, 2009 | Alesis M1-Active MkII Main / Stereo...

1 Answer

Alesis 620 m1 active studio monitors sound cutting out


It could be a power problem, unless you have blown the driver ?, carefully pull out the power supply board, and look to see if anything looks melted, burned, or capacitors popped etc. Be carefull though as I do not want to be responsible if you get an electric shock, etc. preferably look and dont touch, just use common sense ;)

Feb 10, 2009 | Alesis M1-Active MkII Main / Stereo...

2 Answers

Alesis M1-Active left speaker emitts a very high pitched wine that sounds like feedback


have your built-in amp checked for trouble. there should be trouble in the output stage feedback loop. this is something to be done by a repair technician

Apr 11, 2008 | Alesis M1-Active MkII Main / Stereo...

6 Answers

Alesis M1 ACTIVE MONITOR amp circuitry board is ticking


The flashing blue LED and loss of sound on the Alesis M1 powered monitor is caused by failure of capacitor C8 (220uF, 35V) on the power supply board. It dries up due to its proximity to resistor R4 (47K, 2 W) which gets very hot. This is a design fault.

Remove the power supply board (4 corner screws and 2 mains connector screws) and disconnect the two plugs. Carefully desolder C8 and replace it. Its value is not critical (220 to 470 uF will do) but it should be a 105 deg. type, preferably at 50V.

Remove R4 and replace it with a similar resistor with its leads bent so that it is nowhere near C8, otherwise the fault will return. One end may be connected to one of the existing R4 solder pads (furthest from rear of board), and the other to the top end of resistor R3. Check that you have connected it correctly by inspecting the PCB tracks.

Replace the board and all screws and plugs before testing.

Nov 04, 2007 | Alesis M1-Active MkII Main / Stereo...

Not finding what you are looking for?
Alesis M1-Active MkII Main / Stereo Speaker Logo

Related Topics:

1,252 people viewed this question

Ask a Question

Usually answered in minutes!

Top Alesis Speakers & Subwoofers Experts

 Grubhead
Grubhead

Level 3 Expert

4576 Answers

Are you an Alesis Speaker and Subwoofer Expert? Answer questions, earn points and help others

Answer questions

Manuals & User Guides

Loading...