Avid Artist Mix not powering up

[sonolink]

One question: "DC input inductor". Would that be the L7 part?

Cheers
Sono

 

[scott2000]

You can really only guess without having an idea of the circuit by testing and/or have a drawing....

L7 is at the DC  input?

I'd guess there is a good chance it is.....

But I've goofed plenty of things myself making the wrong guess...lol

 

[Khron]

Going by that grainy photo in the first post, the big fat tracks connected to L7 go to the DC input socket (to the "north"),  and the rest of the circuitry (to the "south").

L8 just seems to be some noise filter for the footswitch input.

 

[sonolink]

Ok, so my friend brought the other unit back. It's an MC Control with only 4 faders and a touch screen but the power supply is identical so I guess the power section will be the same.

I checked that the diodes lighting up are the same, so the MC Mix is actually powering up at least partially. I also looked for L7 and L8 since these components were said to have been replaced in further versions of this hardware and they look different indeed:

https://drive.google.com/file/d/16nf6pdaOC1u7pr-icdcShO9Bnw0BrHzH/view?usp=drivesdk

The whole board:

https://drive.google.com/file/d/16kAeNSrDokm51bV40NmOYVGnjVseZF1V/view?usp=drivesdk

Cheers
Sono

 

[scott2000]

Not sure if there's a question in here...??

Probably beefier inductors explains the difference in looks....


Without a drawing, it's kinda just hoping to stumble across the part that isn't working.....but it's totally possible...

should be able to see similarities in the 2 designs since you have them both and take some measurements to see if something stands out as odd..... continuity, resistance....etc..... usually test with power disconnected.....unless testing for voltages or signal...

At least this MC Control board doesn't look as shoddy in the uncleaned flux dept....

an lcr meter would be nice to check caps too since they have been mentioned here as a problem area in the past as well....

 

[sonolink]

I can't measure inductance. Only capacitance and resistance. But to measure properly caps shouldn't I lift one leg of the cap?

Cheers
Sono

 

[scott2000]

I can't measure inductance. Only capacitance and resistance. But to measure properly caps shouldn't I lift one leg of the cap?

How are you able to measure capacitance?

From my experience

When testing caps with an LCR meter, more often than not it will show if something is reading good capacitance while still installed. When it doesn't is  when I lift "a leg" to check if it's circuit related.. Which it is more often than not but not as much ....

With a working unit available, if the circuit is the same, you could  reference the readings between them to avoid having to remove anything ...

 

[sonolink]

Mmm ok

How are you able to measure capacitance?

I use my Uni-T UT71E

Cheers
Sono

 

[parismaison]

Hey, I have the same problem with an MC Mix- wondering if you got anywhere with it? I've probed a bit but with no schematic it's rather difficult to find the fault. I'm reading DC voltages at a few places in the circuit and have the same 2 diodes lighting but wondering if the software switch is broken or something... Not really sure how that works or if it could be bypassable.

 

[sonolink]

Hi Parismaison,
Sorry to say I gave up on it

Cheers
Sono