Author Topic: Help with schematic or pic of DM8 power section (maybe DM10?)  (Read 213 times)

I have searched everywhere and even emailed Alesis to try and find a schematic for the power section on a DM8 module.  If anyone has a link that would be great, or if you actually own one and wouldn't mind opening the case to take a pic of the area behind the power jack.  I know I am missing a capacitor there and I suspect the blown out component may have been a diode.  If I knew for sure, I think I could suss out the rest of the circuit and maybe save this guy from the trash heap.

Re: Help with schematic or pic of DM8 power section (maybe DM10?)
« Reply #1 on: March 19, 2020, 12:56:56 AM »
Turns out it WAS a diode that blew.  1 of 4 that make up the bridge rectifier.  I have tested with a replacement of the same type as the other 3 (B140 40v 1A.)  And It Lives!  No further testing yet.

Unfortunately, when the diode blew it melted down through at least 2 layers of the board all the way into the ground plane.  So I will not easily be able to use the stock barrel jack location.  The plan is to mount a new jack into the lower case and run the wires to safe locations on the main board. 

I also need to look at capacitor C6 which apparently flew away in the explosion.  After studying other circuits from Alesis, I believe this is a small value (.01uf) filter cap going from one input leg to ground.  I will address that later after I have confirmed the rest of the circuits are functioning properly.