Raystar oled : Screen Issue - what I am doing wrong?

[Xavier]

You can ask all the questions you want without any problem on this forum

The OLED mod is described here :
http://ixox.fr/forum/index.php?topic=69159.0
The goal is to prevent the OLED from spreading its 16Khz internal noise through the audio path.
Seems like it also has the advantage to fix the Raystar OLED problem.

The shield provided by Van Daal replaces steps 4 & 5.
You still have to do step 1,2,3 which is not very complicated bur requires soldering and a 22 ohm resistors.

Now, I don't think using a 9V power DC adaptor will fix the problem.

[lokki]

i would at least give it a try with the 9v wall adapter.

that said, the resistor mod is easy to do, the pcb is very nice and easy to solder. the hardest part will be the oled change. cut a leg off and connect a wire from one contact to another.

good luck!!

[SoundRider]

Thanks Xavier for the link ... and your answers 

this gives me at least an idea, what has to be done. Today I carefully opened the box and had a look inside and closed it later. I have not decided how to proceed, but a DIY seems to be feasible. Where could I find a short description for disassembly of the unit? If I try it myself, I would like to know, if there are some tricks or tools I should better know about, before I brake something or end up with a mess

Since I am still in honeymoon with my PreenFM2 and want to continue with creating presets, I don't want to risk a damage or part from it right now. Maybe I will just use it as is for a while, because the sound generation seems not to be affected.

Xavier - this is an amazing synth - thanks for having made this available for us 

[Xavier]

No problem, I don't like knowing a preenfm2 has such an issue.

Read http://ixox.fr/preenfm2/build-it/metal-case/ from bottom to top to disassembly.
- 2 front screws to open the box.
- 4 top screws to separate the PCB from top part of the box.
- 2 last screws on the OLED

As Lokki said, the hardest part is the workk on the OLED itself.
Crefully take off the OLED by puling it from right and left at the same time. Use your 2 hands

Best,

Xavier

[SoundRider]

Thanks for your advice Xavier ... great support ... many kudos 

will check out the link this evening definitely ...

Question ... do I have to disassemble the mainboard from the housing too, to get the OLED and the resistor mod done, or is it the dismounting of the OLED only. Maybe I did not understand the images of the mod correctly? I had the impression, the complete board assembly has to be dismounted from the housing.

[lokki]

yeah the resistor is on the other side of the board (viewed from the top) so you will have to take it out.

[SoundRider]

Thanks, good to know ... maybe if I try and succeed I might become a DIY-er too 

[Xavier]

 
I just received some raystar OLED and i cannot reproduce this problem...
Maybe your USB is a bit higher than 5V. I tried several USB power sources, they gave from 4.7v to 5.01v. The Display worked fine with all of them.

I'd like even more than before knowing whether the mod fix the issue... 

[SoundRider]

Llet me try to check my USB sources ... I will report back, okay?

[served]

Hi.

I have done some extensive research on this.
Ended up wiring the Screen directly to the MCU.
And this was the only way to solve it.

I have had about 10 units with this issue. And wiring was the only way to fix it.

Its not related to voltage as I know.
This issue with the LED to raystar OLED conversion is known over the programming forums. Arduino, raspberry.
Even Sonic Potions LXR is having it.

I don't know what is causing the issue. Some say its the noise. Some say that the code needs to be changed although raystar claims it will work.
Here is something that Julian did
http://forum.sonic-potions.com/discussion/768/display-problem/p1

The issue is in the data, it just gets lost or shifted between the MCU and the screen controller.
Its mostly related to Raystar screens only.

Also, the issue is randomly occuring. If they work after the assembly, they will not work at the client. If they work one day, they will not work the next day.
Using some contact lubrication on the Pinheader will not help.

Second note.
After I implemented the Metal Shield on the OLED display. This has created another issue with the Raystar screen PSU (coil). It starts to make loud whine noise in some cases. Removing the shield, will remove the whining noise. But I have had it only once or twice. And I was able to make it whine again everytime I attached the shield so it was not a random act.

The more I think about it. The more I think that the OLED design is not really implemented correctly. And its not a Plug-and-Play replacement as they claim. It might need a new design of the whole Preen concept (screen related part). Maybe Raystar is cutting costs and skipping something. It should not be that difficult to fix, but as its not a steady issue, then you cant just sit down and start fixing it.

I hope I can get more time to add some input on the issue solving.

[Xavier]

Thanks Ardi for the detailed feedback.

Do you double confirm that the OLED mod that lower the 5V input voltage does not fix the issue ? You saw a moded preenfm2 (22 ohm+pin 2 cut+2 to 15 OLED wring) that still has this problem ?

Just read the LXR discussion. The LXR problem was a boot problem, once the Raystar boots it was OK, if it failed that was from the begining.
The preenfm2 problem when it occures, occures after the OLED worked for some time.
Does not sound like the same.

If you have the URL about this on other forums, i'd like to read.

Thanks,

Xavier

[served]

Do you double confirm that the OLED mod that lower the 5V input voltage does not fix the issue ? You saw a moded preenfm2 (22 ohm+pin 2 cut+2 to 15 OLED wring) that still fails ?

Yes. I confirm that the Resistor change does not solve it. I have made the mod on all the units. And some clients still had it. Running wires directly to the Screen was the only way it went better. But I am not sure its a cure.
Atleast I didn't manage to make it happen again. And I didn't get any bad feedback.


I will look for the forum posts.

[lokki]

other, maybe esoteric question, is there any preenfm2 without metal case and raystar oled that has this problem? ardi wrote about the metal shield adding whining noise in some cases. maybe the raystar is "problematic" with metal cases???

[Xavier]

Yes. I confirm that the Resistor change does not solve it. I have made the mod on all the units. And some clients still had it. Running wires directly to the Screen was the only way it went better. But I am not sure its a cure.

OK. Thanks for the confirmation.

other, maybe esoteric question, is there any preenfm2 without metal case and raystar oled that has this problem? ardi wrote about the metal shield adding whining noise in some cases. maybe the raystar is "problematic" with metal cases???

I'll put a Raystar oled in my metal box tonight.... Thanks for the idea.

[served]

Good question...
A really good question actually.

The Oled screen has a grounded Metal frame (black one). This does provide some shielding. But the electronics is naked. The metal case is not grounded in PReenFM. Its basically floating metal box. So it can act like an antenna. Today with all the interference in the air, it can mess up something.
I will recieve some goods from Xavier soon. Then I can start looking into it.