Replacining Internal Power Supply PCB on Korg Kronos X

juanab · Post by **juanab** » Thu Apr 14, 2022 2:31 pm

I need to replace the Internal Power Supply PCB, (part #500002190400) on my old "Korg Kronos X"

The replacing part for this item was part #500002190402. It is no longer available.

In Spain they have told me that the new part number for this item is #500002190403

The complete name and number they gave me for this item was (in Spanish):
FUENTE ENO-1612-K (IMB-140D-K) KORG 500002190403

Does anybody know if this part (#500002190403) would work properly on my old "Korg Kronos X"?

average_male · Post by **average_male** » Thu Apr 14, 2022 6:18 pm

Spain runs on 220V not 110/120V, so you need to account for this. Are you able to locate a specs for the part numbers you listed?

Update 2:
Looked up the part and found this: https://www.audiotestserviciotecnico.co ... dk-c-korg/

You just need to confirm input voltage and if you don’t mind spending $200++, then it should be fine.

If you are electronically savvy and want a better power supply, I’d recommend installing a Seasonic PSU. There is a post I made that touches a little on this approach.

Update 3:
Seems it is 120v and be fine for North America. See discussion here that notes the model you referenced:
www.korgforums.com/forum/phpBB2/viewtop ... fd92941aa0

juanab · Post by **juanab** » Thu Apr 14, 2022 11:21 pm

Thank you very much, average male!
I am from Buenos Aires, Argentina and my Kronos runs on 220V.
I'll try to get the ENO-1612-K.
Just in case, what Seasonic PSU model would you recommend?
Thanks again!
Juan

average_male · Post by **average_male** » Fri Apr 15, 2022 3:12 am

juanab wrote:Thank you very much, average male!
I am from Buenos Aires, Argentina and my Kronos runs on 220V.
I'll try to get the ENO-1612-K.
Just in case, what Seasonic PSU model would you recommend?
Thanks again!
Juan

My recommendations comes with a condition, the condition is you are pretty comfortable with some basic electronics (no soldering for this is needed). I state this because using a Seasonic PSU will require you to either create an adapter that interfaces with your Kronos' existing power connector/interfaces (this options allows you to easily switch between stock PSU or a Seasonic PSU) or you will need to rewire the Kronos' power connectors to mate with the Seasonic PSU connectors (which is somewhat like ATX scheme), this option isn't swappable with stock PSU connector. Folks who wire customs powering cables for PCs would find either of these approaches pretty straight forward.

With that said, this is the PSU I used, "Seasonic 300SUB" (SSP-300SUB): https://www.tigerdirect.com/application ... 2&csid=_86

And in this thread is a picture of a Seasonic PSU, with the custom adapter approach noted above, in my Kronos 1 73 (minus the PSU cover, which is required for optimal cooling and quiet operation and the cover was put on prior to reassembling the Kronos).

Pictures 7 & 8 show the adapter (adapters really) wrapped in black electrical tape (tape was totally overkill and was just an added measure to ensure the connectors didn't somehow get disconnected).
http://www.korgforums.com/forum/phpBB2/ ... 1da4bed6e9

As noted in the thread, there are many advantages going with a Seasonic PSU, some of which are better capacitors (Japanese caps), better thermal performance (stock PSU has no built in fan, Seasonic has a fan and can be set to come on only when needed), cheaper than stock PSU, easier to source than the stock PSU and the stock PSU has a track record of failing (cheap Chinese no-name manufacturer?).

There are other details not noted above, like you will need to use the existing PSU mounting brackets for the Seasonic which will require you to drill 4 holes in the bottom the Seasonic PSU case and disassemble the PSU to attach the noted brackets. And you will need to wire the main power connector from the Kronos directly to the Seasonic PSU.

It is extra work and this approach isn't for everyone, but if you are willing to take the time, there are a lot of advantages to going this route.

Will be happy to assist if you decide to take on the challenge. Either way, best of luck and may the force be with you.

juanab · Post by **juanab** » Fri Apr 15, 2022 2:48 pm

I really appreciate your help. But I'm really not very tech savvy.
So I think I'm gonna proceed with the ENO-1612-K (IMB-140D-K), the installation of which seems easier.
And once again, THANK YOU VERY MUCH!

BlackForest · Post by **BlackForest** » Tue Aug 30, 2022 5:58 am

Would you mind posting some wiring diagram for the adaptes, and parts needed?

I also got me a second hand "X" and it has the problem of not being able to reboot when it is warm, it only briefly reacts, blinks and then it's off again.
Also the Kronos "froze" yesterday briefly, the screen, and then switched off. so I hope it is not the PSU, but would like to have the information about the adapter ready.

I will first only add a CPU cooler over the heatsink and the other NK10 chip, which gets so hot, and hope it is not the PSU

average_male · Post by **average_male** » Tue Aug 30, 2022 4:23 pm

Hello,

I don't have the part numbers but here is some details to get you started:

IMPORTANT: Always confirm voltages regardless of spec sheets and always double check correct wiring when making such an adapter

1) Pinout for the Kronos Power supply https://www.kronoscopie.fr/fichiers/spe ... cation.pdf

2) Attached Pinout of the Seasonic power supply I used:

https://live.staticflickr.com/65535/523 ... 204f_h.jpg
https://live.staticflickr.com/65535/523 ... 6ba6_h.jpg

3) I had crafted the custom interface between the two using PSU connectors found on DigiKey or similar, example:

https://www.digikey.com/en/products/det ... 41/4119901

https://www.digikey.com/en/products/det ... 140/265718

https://www.digikey.com/en/products/det ... -4N/608626

And something like this for making new female/male connections:
https://www.digikey.com/en/products/det ... 0039/61448
https://www.digikey.com/en/products/det ... 0041/61445

You’ll need to remove the pins from the SeaSonic power supply cable housing and make an interface (requires extra long PCB header pins) for the existing PSU connector on the Kronos and a another 4 pin connector for another board, and I think another connector for the boot support board.

BlackForest · Post by **BlackForest** » Sat Sep 03, 2022 6:45 am

average_male wrote:Hello,

...

Thanks average_male, this does help.

Am still busy with the fans first. I've moved the original fan on the heat sink of the CPU (Kronos X). The temperature was then about 51'C but it still showed the problem of not being able to power cycle/reboot it. It seems to be too warm still? I thought the temperature needs to be under 60'C for this.

I've ordered another fan, same size as the original and will mount one of them to original location so the air flow is reestablished.

Or could this all mean that indeed my power supply is on the way out?
As said the only problem i have is that I cannot reboot it while warm.
It doesn't switch off by itself.

average_male · Post by **average_male** » Sat Sep 03, 2022 3:45 pm

BlackForest wrote:I've ordered another fan...

If you are facing heating issues with less than 30 minutes of usage, I don't think that you are facing a fan issue. The existing fan doesn't offer a lot of cooling to the CPU and motherboard. If you have heating issues after more than 30 minutes of usage, then it could be heat related. The cooler you can get your Kronos, the better it is for the electronics.

You can confirm if this is a hearing issue by opening up your Kronos and while upside down and opened, power on your Kronos and perhaps play a large combi with external keyboard. If you do not have the same issue, then yes, you have a fan/over-heating issue. If do face the same issue, then it could be a number of things and I'd start with the power supply as that seems to be the most common point of failure. You can prove if it is the power supply by temporarily connecting a regular computer ATX (24-pin) power supply directly to the Kronos motherboard. You may need to jump some voltage lines (V5, I believe) for other connections (Korg main audio [ARM] board) and perhaps a sensing line to the motherboard header also. I did this to confirm my first generation Kronos had a bad power supply.

BlackForest · Post by **BlackForest** » Sun Sep 04, 2022 3:47 pm

Well, i have now 2 additional fans: one 60mm on the CPU, and one smaller one on the power supply. The original fan is back at its place. I also stuffed some foam next to this fan to avoid a "short-cut" of the airflow.

With the fan on Auto it stays around 50'C when in normal use (ambient temperature is around 23'). At this device's temperature an immediate reboot is not possible. A few minutes later then yes.
If I leave the Kronos "idling" it goes down to above 40'C.

Is this a normal behavior (Kronos X73) or a possible sign of a dying power supply?

average_male · Post by **average_male** » Sun Sep 04, 2022 4:35 pm

Well, given what you stated, it's difficult to make any conclusions as to the root cause and some diagnostics will need to be performed to isolate the issue. What I noted above is something I would do if I was in your situation.

Additional technical details that may assist. If you look at this link on page 28, you get a sense as to where the Intel motherboard has its heat sensor and the usage of "thermal diode" on the CPU.

https://www.intel.com/content/dam/suppo ... Spec02.pdf

My assumption is that this sensor is used to gauge the Kronos' heat readings and if this is the case, then we need to understand what is driving the heat up so high and preventing a reboot? Have you tried factory resetting your Kronos to factor settings? Other than that, opening up the case and performed the test I noted seems needed at this point.

BlackForest · Post by **BlackForest** » Mon Sep 05, 2022 4:56 am

I don't have a separate ATX power supply lying around to do this test. I had the Kronos open a couple of days ago and seem to remember that it did run cooler while being open and upside down.

BlackForest · Post by **BlackForest** » Mon Sep 05, 2022 5:01 am

Don't know if that makes a big difference -but my MB is a different one. I wasn't able to find out the exact type though. It is Intel, in a Kronos X.

It has the RAM lying flat down just like a laptop, not standing upright like in your supplied data sheet.

Can't remember how to upload pictures though...

average_male · Post by **average_male** » Mon Sep 05, 2022 4:48 pm

BlackForest wrote:Don't know if that makes a big difference -but my MB is a different one...

Ah, ok, that's right, some (all) of the X models had this new board:
https://www.asrock.com//download/e-cata ... Series.pdf

But my suggestions for narrowing down the issue is still applicable.

BlackForest · Post by **BlackForest** » Mon Sep 05, 2022 5:41 pm

average_male wrote:
BlackForest wrote:Don't know if that makes a big difference -but my MB is a different one...
Ah, ok, that's right, some (all) of the X models had this new board:
https://www.asrock.com//download/e-cata ... Series.pdf

But my suggestions for narrowing down the issue is still applicable.

Thanks, yes, I will try this at a later stage. Just for clarification - this is a pic of the MB i have in my "X":

https://drive.google.com/file/d/1Cujc5x ... p=drivesdk