Author Topic: [Solved] preenfm3 controller board acting funny  (Read 159 times)

lokki

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[Solved] preenfm3 controller board acting funny
« on: November 20, 2020, 11:35:51 PM »
hi there,

i am in the process of getting my preenfm3 into a case and i have a very strange problem. i will first list the symptoms and later things i already tried...

all was working fine until yesterday. it has to be said that i did not use a header but a short ribbon cable to connect the two boards.

when i put the mainboard and the control board together with 4 screws, the controls did start to act funny.
-turning an encoder would sometimes not adjust any values, sometimes 3 or 4 at once, with values jumping all over the place.
-pressing buttons results in either no reaction or a white-screen or a screen with coloured lines (segments). the screen usually reboots and displays normally again.

so i took the controlboard off again because i though one of the ribbon cable connections had become loose. holding the controlboard at a certain angle made it working normally again which made me think it was indeed a loose connection.

so i redid the solder on those connections, no change. ok i thought one of the cables has gone bad. replaced the ribbon cable, same behaviour. i measured with a multimeter from controlboard to mainboard and all points are connected.

one thing i did notice when the boards arrived in the mail was that the mainboard was slightly bent, it had a slight curvature. putting the controlboard and the mainboard together may have forced that curvature to become flatter i guess and could maybe have broken some connections on the mainboard?

are any of these symptoms familiar to you? can i somehow test if the mainboard is intact? any other ideas?
« Last Edit: November 22, 2020, 09:43:41 PM by Xavier »

Xavier

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Re: preenfm3 controller board acting funny
« Reply #1 on: November 21, 2020, 07:25:45 AM »
hi there,

when i put the mainboard and the control board together with 4 screws, the controls did start to act funny.
-turning an encoder would sometimes not adjust any values, sometimes 3 or 4 at once, with values jumping all over the place.
-pressing buttons results in either no reaction or a white-screen or a screen with coloured lines (segments). the screen usually reboots and displays normally again.

- "Coloured lines (segments)" is a reinit command send from the pfm3 to the TFT when press MENU + INST- is pressed. So it's supposed to be clean again after 2 seconds.
- White screen is when the TFT receive corrupted data. You can then press MENU+INST- to reset it.

The pfm3 definitely receive bad key press information.

so i took the controlboard off again because i though one of the ribbon cable connections had become loose. holding the controlboard at a certain angle made it working normally again which made me think it was indeed a loose connection.
so i redid the solder on those connections, no change. ok i thought one of the cables has gone bad. replaced the ribbon cable, same behaviour. i measured with a multimeter from controlboard to mainboard and all points are connected.

Multimeter does not send high frequency signal.
The keys data is quite high frequency so it's possible there is some noise somewhere that prevent clean data transmission.

one thing i did notice when the boards arrived in the mail was that the mainboard was slightly bent, it had a slight curvature. putting the controlboard and the mainboard together may have forced that curvature to become flatter i guess and could maybe have broken some connections on the mainboard?

You only need the 5 pins connector + the right pin (top view) of the 8 pins header for the led. Look at the solder point on the PCB make sure they're clean.
Try to focus on that and maybe us a shorter ribbon cable.


are any of these symptoms familiar to you? can i somehow test if the mainboard is intact? any other ideas?

Yes, mainboards are slighly bent but that does not prevent them to working fine at all.
Broken connection (even one) would prevent any data to be transfered from the controlboard to the main board.

It's 100% a connection problem between the mainboard and the CB.



lokki

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Re: preenfm3 controller board acting funny
« Reply #2 on: November 21, 2020, 08:33:47 PM »
Happy to report that one of your solutions did work!

The ribbon was too long! With a shorter one it works absolutely reliably. Great.

When should the top LED light up? Up until now I only had the 5 connections anyways because I figured the rest was not needed (breakout for later use)

Did you see my post in the general pfm2 pfm3 thread? It would be great to have a 100% pdf of the top and back part of the enclosure. That way I could print that out and use it as a drill template for my enclosure...

Thanks!

Megalomidiac

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Re: preenfm3 controller board acting funny
« Reply #3 on: November 22, 2020, 11:57:32 AM »
I have already made a casing design for laser cutting, you could try to mill it. Please wait until tuesday, I am not at home now.
I want to offer the design for free here in the forum, but wanted to order it at  first to test before somebody spoil money.

It is a design like from the Ambika, Anushri and PreenFM2 acrylic casing with nuts and screws.
« Last Edit: November 22, 2020, 12:20:29 PM by Megalomidiac »

lokki

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Re: preenfm3 controller board acting funny
« Reply #4 on: November 22, 2020, 02:16:51 PM »
Ah nice, that could work, what is the file format? I think my display is placed slightly lower/different then the one by xavier, so I will likely have to readjust parts of the case/file

Megalomidiac

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Re: preenfm3 controller board acting funny
« Reply #5 on: November 22, 2020, 03:31:08 PM »
It's in eps/svg format, but I can add PDF if you want. I'm just not shure if PDF will serve the right ratio.

lokki

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Re: preenfm3 controller board acting funny
« Reply #6 on: November 22, 2020, 04:04:23 PM »
Svg is fine, I can work with that, thanks!!

Xavier

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Re: preenfm3 controller board acting funny
« Reply #7 on: November 22, 2020, 05:58:25 PM »
Happy to report that one of your solutions did work!
The ribbon was too long! With a shorter one it works absolutely reliably. Great.

Good news !!!  :)

When should the top LED light up? Up until now I only had the 5 connections anyways because I figured the rest was not needed (breakout for later use)

It blinks synced to external midi clock or with sequencer when it's playing.


Megalomidiac

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Re: [Solved] preenfm3 controller board acting funny
« Reply #8 on: November 23, 2020, 10:45:59 PM »
Here are the casing files.

Please note, that my SVG export could be flawed as I only have an old Illustrator CC.
If there are troubles, please note me that and I could try to export to PDF.

https://www.file-upload.net/download-14376274/PreenFM3Case.rar.html

Also, as long as I didn't ordered them from the factory, these files are beta!

lokki

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Re: [Solved] preenfm3 controller board acting funny
« Reply #9 on: Today at 12:21:35 AM »
Thanks will print them soon and see if they fit :)