Korg Radias PCB fried - need new PCB for repair

PoeticIntensity · Post by **PoeticIntensity** » Wed Jul 31, 2013 7:36 pm

Hey guys... As per the photo (if I can figure out how to attach a photo), does anyone know how I can get my hands on a new PCB (of the 3 PCB boards in the Radias, I just need the narrow one housing all the connectors)

Or, perhaps would anyone know how to fix such an issue? Looks like it's pretty fried to me.

[/img]

axxim · Post by **axxim** » Wed Jul 31, 2013 8:19 pm

Hi Poetic,
From the location and the fried component which I cant recognize I would say it is the power adapter input section. At first I would check the voltage of power adapter if it is damaged. Is it the original one or did you use a replacement? Was there a storm with lightnings near you location recently before the damage?

Since I have no Radias schematics it is hard to say what the damage is, but usually it could have been a capacitor or protection diode that got an overvoltage peak. How deep this effect affected the remaining circuitry is another point that is very difficult to predict. Depending on the cause of the damage, the board could be fixed or a new one would be the solution but only with knowing the cause and the schematics I could make a better diagnostic. Do you know someone with electronic knowledge that may help you? How do the components in the oposite side of that board look? Maybe you can post a picture with the same resolution of that section.

SanderXpander · Post by **SanderXpander** » Wed Jul 31, 2013 8:23 pm

I'm not an expert either but it looks like an exploded capacitor.
If you can find which part is faulty, the actual board is not such an issue. It's just something to keep things in place and connect the legs of the different parts via the paths you can see. If you can still solder a wire to the path you could replace the parts, though it wouldn't look so pretty.

But yes, best bet is to have some electronics repair guy have a look. You'll pay for his expertise but that's better than ruining the rest of your Radias when it could've been a simple fix.

PoeticIntensity · Post by **PoeticIntensity** » Wed Jul 31, 2013 9:58 pm

Here are a few more shots.... Thank you so much for your quick replies!

...and here's one of the back.

Any thoughts?

PoeticIntensity · Post by **PoeticIntensity** » Thu Aug 01, 2013 4:51 am

Oh, also... In response to your question, I'm using the official Korg power cord. No third-party crud here. It came with the unit.

axxim · Post by **axxim** » Thu Aug 01, 2013 5:28 pm

Hi Poetic,
as I said, first I would test the output voltage of the adapter. Second I would check if one of the capacitors (the blue ones at the last photo) have a short circuit. It would also be usefull to know what the designator (the white text on the PCB) nearest to the blown component reads. Maybe you can wipe it with a light moistened nap to remove the smoke traces to find out what it reads. Depending of the starting letter it would be possible to guess waht type of component it was. If you have no or very poor knowledge of electronics then better look for a friend or technical service who can make it for you. Ordering a new PCB without finding out what the cause was, may produce the same damage again. Depending on where do you live it would more or less difficult to find someone who may help you.

X10CIV · Post by **X10CIV** » Fri Aug 16, 2013 12:19 am

Hello PoeticIntensity

Just wondering how you are getting on ?

Here is a link to the RadiasR service manual which may help ?

It may help others too ?

https://www.dropbox.com/sh/1pmscfmrtp9ykdn/izuYC5TjWT

NB: password is: " &radiasr " without the quotes

roberto82 · Post by **roberto82** » Thu Oct 03, 2013 5:35 pm

@PoeticIntensity: Hi Poetic, I think the problem is in the inductor because it blew up due to high supply or whatever due to other reason. If you want to test the inductor then just check the continuity across the terminals of the inductor with the help of multi-meter; if it does not beeps then it is open and you have to replace this inductor.

michu · Post by **michu** » Fri Oct 04, 2013 11:32 pm

X10CIV wrote:Hello PoeticIntensity

Just wondering how you are getting on ?
Here is a link to the RadiasR service manual which may help ?
It may help others too ?

https://www.dropbox.com/sh/1pmscfmrtp9ykdn/izuYC5TjWT

NB: password is: " &radiasr " without the quotes

Can we please get passwords for remaining M3 manuals ?

--edit

Disregard my question. I found the password.
Both pdf for M3 use password: "&m3"

(no quotas used)

alfredokiwi · Post by **alfredokiwi** » Tue Dec 02, 2014 2:28 pm

Hi, please check the PWM switching stage on the mainboard. Korg R3 use a similar switching stage design on 3,3V regulation as Korg TR on 5V. Such design can lead to a sudden short circuit on P-channel MOSFET on PWM switching controller stage when the external power supply voltage drops due DC fluctuations or 110/220v AC issues.

All that is explained here:

http://www.korgforums.com/forum/phpBB2/ ... hp?t=89424