PSU Board repair or replacement Ecler Nuo 2.0 DJ mixer

[eum]

Hi,
I try to repair this fly-back type PSU, I diagnosed (identifiable) dead N-MOS and fuse, but there are 3 smd resistors on the bottom that burned and became unreadable.

The support in charge of the brand in France managed to get me the schematics from Ecler, but it didn't include the PSU board. After a while they finally told me that the unit was too old so they don't have the PSU board schems.

I can find replacement PSU board online, but only for the Nuo 3 or 4 or 5, and it seems they ar compatible with each other, as I often find boards compatible with these 3 Nuos.

Funnily, Ecler won't share the service manuals for the newer models either.

My board version is : 11.0864.04, and it has what looks like 2 bipolar outputs.
Each one having a black, yellow and brown cables, and 2 470μF output Rubycon electrolytics, rated for 35V, so maybe for ±18 or 15V outputs.

If someone can send me a readable pic of the bottom of the PSU PCB I may manage to fix it. But maybe there is conception error hat makes it useless to repair, just to see it fail again a while later.. But, according to the SM, just on the Nuo 2.0 mainboard there have been several revisions, so it may be also true for the power board...

Does anyone know or can measure the output voltages of the PSU for Nuo 2.0, 3, 4 or 5 ?

Thanks,

Eum

[petehall347]

Re: PSU Board repair or replacement Ecler Nuo 2.0 DJ mixer

look up whatever burned the resistors and see if there is a suggested circuit for it ..

[eum]

Re: PSU Board repair or replacement Ecler Nuo 2.0 DJ mixer

There is a MOS driver for fly-back application (UC3842BDG).
I had downloaded its datasheet, but was not convinced I could find like that.
You gave me the punch to go look deeper in it, thanks !

It seems those are 3 paralleled resistors between the switching N-MOS and ground.
I guess they put 3 to dissipate heat more easily with basic CMS.
It's supposed to be 0.5Ohm, based on the Figure 35, "27W Off-line flyback regulator", page 16 of On Semi's datasheet.

There is an additional Zener on the PCB that I don't see in datasheet's applications, where it's always between pins 8 and 10 (SOIC14 version, here), unlike in my case.

Well, maybe I'll try to find a 4W (roughly), 0.5Ohm and also replace the dead Mosfet to see what happens..

But again, if anyone has one of those machines, and would be kind enough to go look / probe inside, It'd be good too

[eum]

Re: PSU Board repair or replacement Ecler Nuo 2.0 DJ mixer

Little update.
I tried like I said, with 0.5 Ω sensor Resistor, and it didn't start. It didn't burn either though.
I'll dig deeper, maybe I can find a PSU calculator using this chip, or an application note.with more precise data.

[eum]

I finally found a work around : add two 18V 40W PSUs in series. The only prerequisite is that the selected PSUs are not ground referenced, otherwise, it would put one output to ground and not work.
I found that those XP Power Model FCS40US18 could be fixed using the old screw holes. 2 of the 4 for each of these smaller boards, in diagonal, but it was a few mm farther so I had to pinch the edge of the board between washers. I added spacers to the remaining holes so that it won't bend too easily.
Lastly, each of these PSUs is rated at max. 1.2A input, so the smaller 0.5A fuse needs to be replaced, I had 2.5A to hand, that should be good.

Now it starts ok, but it outputs a low frequency, when the faders levels are at their minimum ! Maybe a grounding issue or something .. (?)

[eum]

Definitely mains irradiating the circuits board, I tried to shield the PSUs in a DIY manner, but it wasn't effective.

[eum]

It seems the mixer cant operate powered by +/-15V instead of the original +/-18V.
If so there are several power supplies available, of which some are shielded.
I'll do some tests and update soon.

[dragos.gogan22]

Hello,

The power supply of my NUO 4.0 died as well after someone spilled a drink on the mixer. I don't know exactly if the values are matching, I hope so tho. I know the values of the SMD caps as well, except for the 2 black ones, if you were searching for those too.

I tried repairing the unit, but since I didn't know the values of those 2 caps and I found a website that is selling a newer 2017/2018 version of the power supply, instead of this one, I purchased one new. I'm going to put the mixer back together soon.

It might work with the 2.0 too, so if you need the website, here it is. You can ask them if they have it in stock and if it works for the 2.0, here's the link: https://www.music-center-shop.com/fr...400-neuve.html

Hope this helps!

[eum]

Hi,

I actually found a complete mixer with working PSU for less than the price than the new version you shared. (I could fix the mixers' output board quite easily, but otherwise it would have made me a good PSU source.)

It seems there have been plenty sub-versions of those PSUs.

What black SMD caps are you talking about ?
(The little squares you show on your picture are in fact resistors, and the number on it codes for the resistance in Ohms : 1211<>121x10¹=1210Ω, 4753<>475x10³=475000=475kΩ.)

I've recently heard that mains film capacitors (X2, Y2,..) can fail too !
It seems they are often undersized...
I measured the capacitance of those on my dead Ecler PSUs boards, and they were really bad.
I'll update when I test with more robust parts (a bit more capacitance and voltage rating : 275>350VAC and 150>220nF).

The previous PSUs on the 2 Nuo 2.0 (and others from the same era) I opened, all had 2 ±18V outputs (symetric). If you can measure on the external pins +18 and -18VDC using the center pin as ground on your newer version, we can conclude they are compatible, and probably better versions.

Finally, I could start one of those Ecler mixers with a standard +/-15V PSU, but I still have to test it in real conditions.

[eum]

I think you should check that your mainboard isn't short-circuit to prevent killing your brand new somewhat expensive PSU.
You can measure the resistance between the pins on each power connector.
Each has 3 pins with the ground in the middle.
If any combination of 2 pins display 0.0Ω for more than a few seconds, it means it is shorted and you have to fix the mainboard first before applying power again.

Hope this helps,
Good luck

[deetee4252]

Hello,

The power supply of my NUO 4.0 died as well after someone spilled a drink on the mixer. I don't know exactly if the values are matching, I hope so tho. I know the values of the SMD caps as well, except for the 2 black ones, if you were searching for those too.

I tried repairing the unit, but since I didn't know the values of those 2 caps and I found a website that is selling a newer 2017/2018 version of the power supply, instead of this one, I purchased one new. I'm going to put the mixer back together soon.

It might work with the 2.0 too, so if you need the website, here it is. You can ask them if they have it in stock and if it works for the 2.0, here's the link: https://www.music-center-shop.com/fr...400-neuve.html

Hope this helps!

I registered just so I could say thank you for posting that link! My Nuo 5 went POP! yesterday.