Re: Repairing Alesis M1 Active mk2 Monitor Speakers



Yes, it seems to be a bad design, the 330uF cap is very close to a power resistor, that heats it and dries the cap, leading in my case to the explosion of the cap, and in a chain reaction, took with it all those parts.
In the repair, I left the new cap with long pins, over the power resistor, hoping it don't heats so much. I was hoping to put it under the pcb, but there's no space....

Re: Repairing Alesis M1 Active mk2 Monitor Speakers

I fixed it!
These are the photos of the repair, not so beautiful, but it's working.
Very nice sound, wish I could keep it...
How much can I bill for this kind of repair?
I replaced 4 x 1n4007 diodes, 2 x 1n4148, 2 irf840, 1 x 470 ohms, 1 x 330uF, 1 x 1uF, 2 x 390uF and the UC3842 ic.

Thanks....

Re: Repairing Alesis M1 Active mk2 Monitor Speakers



No, unfortunately there's no sign of the tracks, just the bare fiberglass of the pcb.

There seems to be another M1 where this came from, I'll go check and see if I can get a photo of the smps.

Thanks...

Re: Repairing Alesis M1 Active mk2 Monitor Speakers

Hello everyone. My father gave me this Alesis M1 Monitor to fix, but when I opened it, I found some traces blown. Now I don't know where they go. With the photos posted by firespace, i could figure out the top traces and the value of the blown resistor (470 ohms), but I don't know where the bottom traces go. I'd like to fix this monitor just for the fun of hearing it a couple of weeks. Does someone have a photo of the bottom part of the power supply?
Parts checked bad: 2 diodes, 2 mosfets, 1 resistor, 2 capacitors, 2 main...