Nord User Forum

EDIT: i just found out i was mistaking cause of lack of concentration, the regulator is LM2940 not LM3940 which is fine, sorry to bother anyone.

cheers.

Hi Guys.

new user here
i got nord lead 2 as a gift from a frien, i have some issues with it.
when turning it on it wont boot up, so i open the NL and sniff around, after soldering few areas that looks suspicious it turn on but not at first time, i need to turn it on wait a bit, turn it off, and turn it on again, after a sec the NL is turn on and working.
so it seems to me like a an electrolytic cap problem to me.
ive tested the power supply board and this is what ive found..
i think i found a flaw in the power supply section, the main power brick is outputting 4x 6V outputs 5.5A for each output,
each output goes to a diodes and regulators that gives +12V, -12V, +3.3V and -5V.
the regulator of the +3.3V is LM3940 which according to the datasheet, the max V in is between 4.5V to 5.5V, when measuring with multi i read 7.4V at the input and 4.95V at the output.
from the power brick, it goes directly to 4,700uF for filtering and from there to the LM3940 regulator.
i'm thinking to my self, why they used the 6V output power brick while the real output is 7.4V and the max V in of LM3940 is 5.5 when it should be 3.3V?
if they needed to use 5V instead of 3.3V why not to use 7805 instead?
isnt this a flaw?
what do you think?

cheers,
Isak.

Hey, man.

I must thank you for that info about NL2's power supply section: I have some boot issues, too, and definitely looks like an electrical/PSU problem to me (with my NL2).

I've been looking for solutions or hints to solve this power supply section issue, and seems like everyone who owns a Nord Lead (1, 2, 2X, 3, 4 and their rack relatives) deals with this problem, eventually. Some Reddit users say it could be simply a bad choice from Nord using such bad, insufficient PSU's in the first place. So far, I've found nothing about a once-and-for-all solution or a detailed explanation (just like you did after your own research) about the why's and how's when your Nord is not booting as it should.

So, I have some questions for you:

1) Did you changed the power supply powerbrick inside the board?
2) If you did changed de PS powerbrick, where did you get the right model to supply sufficiently the outputs?
3) Did you desolder/resolder something else from the power section to solve the problem?

I'm also looking for solutions for this thing, 'cause if I wanna use my Nord Lead 2, I have to turn it on and wait for... +8-11 HOURS! (No kidding at all) so the boot can be done properly. After all that waste of time/electricity, everything works A-OK and the sound is clean and nice as usual. It seems like the headphones output throws some low noises and saturation-like sounds (so bad there's not such a thing as a headphone level knob to finetune that, because that output is loud af), maybe it's just some dust inside that jack.

Anyway, would be great to find out how did you work on the power section with your Nord so I can give a try on mine.
Hopefully, we can finally work this out.


Thanks, bro!

Trying to bump this thread...have you had any luck, Miguel? I've got what seems to be a bricked out Rack 2. A friend whose good with electrical stuff thinks the transformer is bad and that a new power supply is necessary. Problem is that I can't find any for sale.

Moreover, does anyone know whether you can swap out the power supply from a different model (maybe the 2x)? Thanks!

If the transformer is bad why not just replace it and repair the PSU?

Also, transformers *rarely* are the failed part in a PSU. If you're not seeing the intermediate rails powering the regulation stage, capacitors are typically the first to go, and over long term, diodes too. Check the fuse, of course, because you might just have a blown fuse. If the transformer is in fact the failed part, it probably means other parts failed first, but as a first inclination, I suspect that may not be a complete diagnosis. Cascading failures do occur in a PSU, so it may be more than one thing in total. A careful diagnosis and repair procedure must be followed by someone competent to work with power electronics, but it's a fairly straightforward PSU so I don't expect it should pose any issues to someone moderately skilled.

[Edited for clarity and expansion.]

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