Replacining Internal Power Supply PCB on Korg Kronos X

average_male · Post by **average_male** » Mon Sep 05, 2022 6:21 pm

BlackForest wrote: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"...

Interesting, looks like the D510MO with just a different type of RAM slot, seems that is laptop RAM, maybe a bit lower power consumption and faster?

average_male · Post by **average_male** » Tue Sep 06, 2022 10:29 pm

Just realized my old Kronos had the same motherboard as yours with the laptop RAM slots, it is the Intel D525MW

https://www.intel.com/content/www/us/en ... tions.html

BlackForest · Post by **BlackForest** » Wed Sep 07, 2022 4:17 am

average_male wrote:Just realized my old Kronos had the same motherboard as yours with the laptop RAM slots, it is the Intel D525MW

https://www.intel.com/content/www/us/en ... tions.html

Ah, interesting. I always thought they had basically two models of MB, now it seems even more.

Just on a side note - I've checked my Kronos LS and it's running in 58'C - without any reboot issues.

jantoman · Post by **jantoman** » Sun Sep 11, 2022 8:46 am

@average_male: thanks a lot for your extra-useful informations! A friend asked my help for a similar issue and tomorrow I'll try to check if his PS needs to be replaced or not (BTW I have a 1st-gen 61 Kronos as well).
Did you look at the ENO-1612-K capacitors when you took it off? I was wondering about recapping it to see what happens... It's not my usual approach on any other gear, but over the years I found out that power supplies are so prone to capacitors' failures that I never think about it, I just replace them at once

BlackForest · Post by **BlackForest** » Fri Jul 07, 2023 9:58 am

So, I might be going to swap the power supply after all..

My Kronos X keeps cutting off sounds, mainly the SXG piano sounds it seems (while sound from other engines continue),
as well as the SSD light then keep blinking and the CPU is super busy (no reaction to buttons or touching the display, to then suddenly catch up with all inputs I did).
I swapped the SSD recently, but this didn't help anything. A disk check showed no errors. An I still have the issue that one can't restart the synth once it's warm.

I found the following PSU but am not sure if the amps of the -12V supply is suffient (it supplies 0,3A while the original ENO-1612 delivers 0,5A).

Will this differnce become an issue, what do you guys reckon? AFAK -12V are used for serial ports only, but also possibly the A/D converters?

https://www.bicker.de/en/beh-531h_indus ... dc_62368-1

Maybe someone in Europe knows another replacement eben cheaper (wanting to avoid tax and customs with US imports)?

Am not sure if I will replace the complete wiring harness of the Kronos, or if I re-plug the exisitig harness (take all the pins out and insert them into the new Molex plug). I will not do the adapters as written above as this is too complicated for my brain...a

KK · Post by KK » Fri Jul 07, 2023 1:56 pm

How old and full is your SSD ? This because if you go on the Nautilus forum, you will see many have a similar problem and Korg apparently suggests to change the SSD (because the original SSD they install at factory doesn't have a very good performance and is already quite full). Disregard this though if you already changed the stock small SSD on your Kronos for a larger sized one.

BlackForest · Post by **BlackForest** » Fri Jul 07, 2023 2:00 pm

KK wrote:How old and full is your SSD ? This because if you go on the Nautilus forum, you will see many have a similar problem and Korg apparently suggests to change the SSD (because the original SSD they install at factory doesn't have a very good performance and is already quite full). Disregard this though if you already changed the stock small SSD on your Kronos for a larger sized one.

Yes, thanks, I've replaced it recently with a 250G Samsung Evo. I did clone it though, so I can't rule out any errors being copied.

KK · Post by KK » Fri Jul 07, 2023 6:22 pm

Hi BlackForest,

Next time you experience the problem go in Global Mode and select the Fan setting option in the upper right menu, then check the temperature shown. Maybe your fan doesn't cool your Kronos enough and the SSD freezes to protect itself if its internal heat protection kicks in. IIRC the earlier versions of Kronos had an off option for the fan, make sure it is not set to off. I could be totally wrong, but just in case.

voip · Post by **voip** » Fri Jul 07, 2023 7:58 pm

The temperature sensor is located on the CPU die itself. It doesn't measure the temperature of the SSD.

.

cjfox · Post by **cjfox** » Fri Jul 07, 2023 8:33 pm

My original Kronos 61 had the same symptoms, piano not working, SSD LED on continously, unresponsive after an hour or 2. No overheating though, below 50C at the time. This was after replacing both the motherboard and the power supply. I put a new 64gig SSD and did a full re-install from DVD, which cured the problem. This was after a long and previously documented journey of repair, which involved putting in more fans, changing a BIOS setting in the new MB, and squeezing in a replacement power supply that was a generic ATX of the same dimensions. Unfortunately, I know you can't do a re-install on an SSD as big as yours from DVD, so perhaps an error is being copied in the cloning process.

BlackForest · Post by **BlackForest** » Fri Jul 07, 2023 9:00 pm

Hm, alright that's a "sad" story of yours, replacing expensive hardware to no avail.
So, if I indeed opted to reinstall, I then would have to reinstall the original SSD first since the larger new SSD would not be recognized by the DVDs, correct?

cjfox · Post by **cjfox** » Sat Jul 08, 2023 5:45 am

I can't remember what the limit is, a 64 gig will work and are somewhat cheap these days.

BlackForest · Post by **BlackForest** » Sun Jul 09, 2023 7:27 pm

So, duh, I tried to reinstall the OS. At first I tried with the currently mounted 250 GB SSD - and it started up to formatting but then got stuck. So, Ok, I got it and I put the old original SSD in. But now the DVD drive is not recognized anymore. It shows an system failure error and says to unplug usb devices. Doing that, it continues to boot alright.

But as said, the previously recognized drive is now not being recognized anymore.
I wonder if it has to do with not putting all the screws of the bottom cover back in ? I can't imagine it, but also, am just tired this evening to continue...

BlackForest · Post by **BlackForest** » Mon Jul 10, 2023 3:01 pm

Tadaa! Step one successful! Quick prayer, I opened this old DVD drive (DVDRW16x2U) , it's from Iomega. What did I find? A good old IDE connection and a jumper set to Slave..So, replug it to Master , and, voila, it"s working!!
Maybe something for some other drives to consider?

projectaspen · Post by **projectaspen** » Sat Sep 16, 2023 1:17 pm

Hi,

could you give more details on how you connected a Seasonic PSU to the Kronos? How did you make the adapter?

average_male wrote:
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.

Korg Forums

Replacining Internal Power Supply PCB on Korg Kronos X

PSU assembly details