OLED screen buzzing

[CelticSoulMan]

Hello gentlepeople,

Nord Grand, Silent in operation until two weeks ago, now an electrical fizzing from the OLED screen. I’ve a vast experience in broadcast tech, and the last time I heard high frequency voltage output oscillation from a screen was a phasing CRT.
Sound tech UK don’t wish to fix issues, it would seem, and the retailer (who is one of the good guys) has just posted a video of a shop floor model displaying same fault. Why do folks believe this to be normal behaviour for a failing component?
Cheers, look forward to the replies!

[pterm]

Welcome to the Forum!
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This topic came up before:
nord-stage-forum-f3/oled-displays-nord- ... ed%20noise
post124460.html?hilit=oled%20buzzing#p124460
OLED modules often contain a boosting power supply (either a charge pump or a DC-DC boost converter) to power the OLED panel. These boost supplies often generate audio-band noise from their components: Magnetic components like wire-wound inductors or piezoelectric components like ceramic capacitors either move or change shape with changing voltage. This makes them audio transducers.
Also, some DC-DC converters change their operating frequency or duty cycle to adapt to changing loads. This might explain why you didn't notice the noise at first.

In my opinion, this noise seems within normal expectations for an OLED powered from a single digital supply.
Normal does not however mean desirable: Nord's specialize in superb samples and intuitive user interfaces but their hardware design choices leave room for improvement...

I own an Electro 3HP, whose keyboard makes many interesting noises, but if instead I listen to the music it makes, I stop noticing the mechanical and electronic noises. Hopefully this occurs for you too.
-pterm

P.S. Please link to your retailer's video (cited in your post) if possible. Thanks!

[LewTheKeysGuy]

Hello gentlepeople,

Nord Grand, Silent in operation until two weeks ago, now an electrical fizzing from the OLED screen. I’ve a vast experience in broadcast tech, and the last time I heard high frequency voltage output oscillation from a screen was a phasing CRT.
Sound tech UK don’t wish to fix issues, it would seem, and the retailer (who is one of the good guys) has just posted a video of a shop floor model displaying same fault. Why do folks believe this to be normal behaviour for a failing component?
Cheers, look forward to the replies!

I too have some experience and background with Sound Technology UK, so you're not the only one.

The buzzing of the OLED is perfectly normal because of the way it is powered and components used. I've owned virtually every nord product in my previous studio and now a stage 3-88 after a number of replacements in the last few months, due to carriers damaging equipment, one model sent which had been a return and missing items, etc. I now have my stage 3-88 and nord grand, both have the display hum and to me that's no issue. I've worked with hardware with humming power supplies, etc it's just part of electronics nature. You will know when there's something to worry about IF either of the modules start erratic functions, line out ramping (headphone and main outs), amongst other things. If that's the case then get it replaced.

As Pterm rightly says regarding components driving the display, this is indeed normal.

lew

[CelticSoulMan]

Thanks for the replies people, all very helpful. I guess I’ll fix it myself and just send the criticism to Nord. If they can’t get a screen to function and/or repair, then it’ll be last Nord I buy, sadly. £3000 to be treated like an idiot by Sound Tech isn’t something I wish to put up with.

[Mr_-G-]

Rather than fixing it yourself (what would that fix be BTW?) I would let Nord know and talk directly to the Service in the UK to understand what is the situation. I doubt it is whether "they wish" to do it or not. The service guys probably follow the guidelines from Nord (who are the ones that ultimately source the parts and pay for the service). I remember somebody posting here that buzzing transformers are "a non-serviceable issue" according to Nord. Maybe the buzzing OLEDs are of a similar nature (i.e. not ideal, but do not affect the function of the instrument and are not really "failing components" either).

[LewTheKeysGuy]

Thanks for the replies people, all very helpful. I guess I’ll fix it myself and just send the criticism to Nord. If they can’t get a screen to function and/or repair, then it’ll be last Nord I buy, sadly. £3000 to be treated like an idiot by Sound Tech isn’t something I wish to put up with.

Forgive me for saying this, but as Mr-G has said, "what fix?" There is nothing to fix. There is a transformer system inside the stage 3, Nord Grand and other nord products where there's a direct IEC type connection, part of the transformer and power rail handles the OLED display, within the OLED display is an inverter component, which due to the hz / khz / mhz measurements, it will create a buzz, this is ABSOLUTELY NORMAL and DOES NOT NEED TO BE FIXED unless the noise then produces a harmonic and an extremely high, annoying pitch to the ears, which means that part of the power rail caps has failed or the OLED Driver fails, you'll know when that happens for two symptoms, 1: the smell, 2: No display or a single colour (white) would occur, then to fix that issue requires an OLED display driver, Display module itself and checking the +5V Rails (my measurements of voltage to the rails might be a bit out)

Please understand where I'm coming from here like many others, we work with these machines every day, personally or professionally, as musicians, sound programmers, etc. Yes, there's some quality Control issues that might creep up, been there, worn the shirt, but that said, I've had god knows how many nord rigs in my studio, each one with a display has produced the same hum and is normal. it's not a manufacturing fault trust me.

For me, I'm blind, yet I can tell a fault on a board, I have a background in this kind of work so I'm used to it. I had a power conditioner in the studio which was a series of 2U racks grouped, when switched on in sequence mode, there would be this hum, including a square wave tone that was out of sync with the hum, sounded nice to me but others who came in, couldn't stand the hum. there was no problem with it as it was inspected by the manufacturer, it was due to the number of power rails, conditioning modules and 2 backup batteries with controllers working together. So, I'd know if my rigs were acting up. I had a Roland D50 which was failing, PSU was whining and humming like a welding transformer, took it out, replaced it with a newer transformer and replaced the socket mount, fixed, but as I say, that was the PSU.

Please, DON'T take this apart and try to fix it, you VOID your warranty with the dealer and Sound Technology will not accept this. Yes there are issues with Sound Technology UK at times, but most of the time they do look after us in the UK. If you're really not that happy, please take it back, get a refund and find another manufacturer. Sorry to say it but you want to fix something which isn't broken. It works, switches on, performs for you, the display creates a noise, normal sound, like korg's oasys workstation and a few others I can think of. it's fine.

Please, just enjoy your board, it's a lot of money to shell out on. I'd understand if the board had been damaged in transit, you'd had issues with various parts of the instrument, but a display module using an OLED and driver combination, it's fine as it is, no faults, nothing.

[CelticSoulMan]

“unless the noise then produces a harmonic and an extremely high, annoying pitch to the ears”

This is what I’ve been saying. The longer the unit is on, the worse the it gets. The pitch is from behind the “3” button below the screen. I can’t see how this isn’t a fault, considering it was totally silent since new, and now not.
Ridiculous that Nord repair tech (with a past history of problematic repairs for different company) can simply overrule an issue I’ve raised to avoid servicing under warranty, and a retailer left to foot the cost of return, which ultimately is passed to me. The piano is three months old!

[fieldflower]

If it is loud enough to present an actual problem, then it is a fault.
If You can demonstrate it to the retailer they should take it seriously and make sure it's fixed.
Some OLED buzzing is to be expected, but if it's actually loud I'm sure Nord would also see it as a problem and exchange for an OLED that buzzes at normal levels.

[LewTheKeysGuy]

“unless the noise then produces a harmonic and an extremely high, annoying pitch to the ears”

This is what I’ve been saying. The longer the unit is on, the worse the it gets. The pitch is from behind the “3” button below the screen. I can’t see how this isn’t a fault, considering it was totally silent since new, and now not.
Ridiculous that Nord repair tech (with a past history of problematic repairs for different company) can simply overrule an issue I’ve raised to avoid servicing under warranty, and a retailer left to foot the cost of return, which ultimately is passed to me. The piano is three months old!

The only thing I can then ask is this. Record a video of this so we can hear it. I'd have chance to listen to it myself, then I can tell you they can replace it.

the issue is this and it's straight forward, all nords produce OLED buzzing where there's an OLED display, it's the driver, inverter and rail doing what it should do. if the noise in question is intensive, to the point where your ears are hurting, etc then there is a clear fault.

All I can ask is that you record the noise so we then understand your problem and then advise accordingly.

If you're genuinely concerned, get the dealer to resolve it. you have a minimum 1 year warranty as per Trading Standards Act 1979. If the product demonstrates a fault then use section 5 of the trading standards act 1975 whereby the product is not fit for purpose due to manufacturer fault. By law, the retailer can replace or have it repaired, If the retailer fails to do this, then it's time to invoke Trading Standards laws through the Small Claims Court. this is a governance of the UK only and not directed to other countries as they have their own laws of product fitness and trading regulations.

I hope this helps.

lew

[CelticSoulMan]

Thank you, Lew, and all.
I’ve recorded some audio and will link it when uploaded.
I was also thinking that frequency and ear age may play a factor in the “annoyance” of the high pitch and certainly the brick wall the piano is sitting in front of is reflecting frequencies back. Still, shouldn’t be that distracting.