Kronos won't boot (SOLVED)

[Knave101]

Several months ago our keyboardist starting having problems with his Kronos. It started to not boot up. We noticed that rolling the board around would sometimes get it to start. So as the "technician" of the band I decided to get to work.

Upon opening the board I noticed one thing...2 of the motherboard screws were gone. and the board tended to flex. I thought this might be the reason...but all attempts to put it back wth new screws did nothing.

After many hours, I jumped the Green Wire (5V) on the ATX connector to ground and the fan would start and the Kronos would also start running, but would stop about 1/5 of the way and send an error code. But at least this allowed me to measure the output voltages of the power supply. All Good. This has a standard 20 pin ATX supply and voltages/pins can be found on google easily.

I still believed it was a mechanical board failure. I checked all solder joints, and moved all the plugs. rechecked the RAM, the SSD, and every connection point, thinking that all the flex in the MB with two screws missing had damaged a solder joint somewhere.

Finally, while flexing the small 'mini-connector' and 'mini-board' at the lower right of the MB, near the keys/power supply, I noticed one pin didn't flex. The 5th pin. It had broken off at the board itself. So this made detection almost impossible. I jumped this pin and the keyboard soared back to life...problem solved.

You don't have to remove the key bed to complete this repair (though it makes it easier for sure) and this little board should be checked if you have the same problem. From what I'm reading, these units frequently lose MB screws due to vibration from gigging and travelling. This MB loosening is the fundamental problem that caused the pin to crack.

No new MB, no new PS. I was minutes from putting it in the closet for a few years. I used thread lock when I put the MB screws back in. Hopefully, they will hold.

Hope this helps someone else. If you need any info let me know.

[GregC]

Several months ago our keyboardist starting having problems with his Kronos. It started to not boot up. We noticed that rolling the board around would sometimes get it to start. So as the "technician" of the band I decided to get to work.

Upon opening the board I noticed one thing...2 of the motherboard screws were gone. and the board tended to flex. I thought this might be the reason...but all attempts to put it back wth new screws did nothing.

After many hours, I jumped the Green Wire (5V) on the ATX connector to ground and the fan would start and the Kronos would also start running, but would stop about 1/5 of the way and send an error code. But at least this allowed me to measure the output voltages of the power supply. All Good. This has a standard 20 pin ATX supply and voltages/pins can be found on google easily. You don't have to remove the keyboard to complete this repair and this little board should be checked if you have the same problem. From what I'm reading, these units frequently lose MB screws due to vibration from gigging and travelling. This MB loosening is the fundamental problem that caused the pin to crack.

I still believed it was a mechanical board failure. I checked all solder joints, and moved all the plugs. rechecked the RAM, the SSD, and every connection point, thinking that all the flex in the MB with two screws missing had damaged a solder joint somewhere.

Finally, while flexing the small 'mini-connector' and 'mini-board' at the lower right of the MB, near the keys/power supply, I noticed one pin didn't flex. The 5th pin. It had broken off at the board itself. So this made detection almost impossible. I jumped this pin and the keyboard soared back to life...problem solved.

No new MB, no new PS. I was minutes from putting it in the closet for a few years. I used thread lock when I put the MB screws back in. Hopefully, they will hold.

Hope this helps someone else. If you need any info let me know.

thats a good report and tricky fix.

Lets zoom in and get a better visual. I believe Kronos uses a
Atom D510 CPU on Intel ITX motherboard:


Lets google

Atom D510 CPU on Intel ITX motherboard kronos keyboard

There are several photos. If you have a few minutes, spot the best photo and define the culprit- the ' mini connector '

What do you believe the cause of the flakey connection ?

Poor assembly ?

Shaking the Kronos around - as in lots of gigs over a period of time ?

Thanks

[Knave101]

Here is the connector with the broken pin. The screws coming out of the board seem to be a common problem among users. This is due to the movement and gigging. This is a serious design flaw...that may have been fixed on later models. (in my past life I was a reliability engineer at a major aerospace firm).

Interesting, my keyboardist has an old Triton that he gigged for a decade or more....still working. The MB screws are the issue. because when they fall, the MB is upside down and flexes, particularly during movement. It must have put too much pressure on the pin. I've marked the pin that broke with a red dot. It was difficult to see until i flexed the little standoff board around and could see that the 5th pin was not moving...cause it was broke. It broke just beneath it's solder joint...so the solder joint appeared fine, and the pin itself appeared fine....it was broken exactly where it passed into the board.

So i pulled out the broken pin and replaced it with a small wire that I tied to the remnant of the post.

I would assume that others have screws falling from their MB.....you can usually hear them rolling around. If so....then the board is flexing, and something is bound to give. In this case a new MB would not have solved the problem....because in this case the problem was in this small standoff board.

[img[/img]

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[GregC]

Here is the connector with the broken pin. The screws coming out of the board seem to be a common problem among users. This is due to the movement and gigging. This is a serious design flaw...that may have been fixed on later models. (in my past life I was a reliability engineer at a major aerospace firm).

Interesting, my keyboardist has an old Triton that he gigged for a decade or more....still working. The MB screws are the issue. because when they fall, the MB is upside down and flexes, particularly during movement. It must have put too much pressure on the pin. I've marked the pin that broke with a red dot. It was difficult to see until i flexed the little standoff board around and could see that the 5th pin was not moving...cause it was broke. It broke just beneath it's solder joint...so the solder joint appeared fine, and the pin itself appeared fine....it was broken exactly where it passed into the board.

So i pulled out the broken pin and replaced it with a small wire that I tied to the remnant of the post.

I would assume that others have screws falling from their MB.....you can usually hear them rolling around. If so....then the board is flexing, and something is bound to give. In this case a new MB would not have solved the problem....because in this case the problem was in this small standoff board.

g]

Thats excellent and easier to see ( for me).

Do you recall which Kronos model you worked on ? The Kronos 2 ( K2) is distinct with its wooden side panels. Korg announced the K2 November 2014.

Prior models were the X in 2012 and the original K from 2011.

And do you recall the key size you worked on ?
The key size might be important in that the sheer mass/weight of the 88
might create more 'flexing ' vs a smaller key size such as the 61.

From what I read in your excellent post, the 'flexing ' of the MB puts pressure on connectors and possibly other areas. And regular gigging, or regular movement
is placing pressure on the MB and corners etc where it is attached.

[Knave101]

It is a Korg Kronos- 88. Purchased in 2013. Serial number below 003500. Intel D510MO. Plastic ends.

If any others have this problem....definitely check the little standoff board, "KLM-3008". Check continuity between the pins and the solder joints, on either side of the MB. If they are discontinuous....that may be problem.

Hope this helps someone else, because I have looked and looked and never seen anyone with a similar fix. Everybody talks about resetting the RAM, etc, but this is the first mechanical fix from what must be fairly common...if these motherboard screws are falling out. This board has not been gigged out much at all, less than 50 times since new, and in a road case.

[GregC]

It is a Korg Kronos- 88. Purchased in 2013. Serial number below 003500. Intel D510MO. Plastic ends.

If any others have this problem....definitely check the little standoff board, "KLM-3008". Check continuity between the pins and the solder joints, on either side of the MB. If they are discontinuous....that may be problem.

Hope this helps someone else, because I have looked and looked and never seen anyone with a similar fix. Everybody talks about resetting the RAM, etc, but this is the first mechanical fix from what must be fairly common...if these motherboard screws are falling out. This board has not been gigged out much at all, less than 50 times since new, and in a road case.

what you say makes sense; I recognize that part #
http://www.korgforums.com/forum/phpbb2/ ... eb15a96308

What you are reading these days is mostly guesswork from Kronos 2/K2 owners.

There isn't a nice data base with solid quantifiable details that supports troubleshooting and what to fix. What we have is trial and error.

I think the Korg service cos should have a good handle on the root cause of problematic Kronos' , all 3 models.

Like you suggest, one would hope Korg learned from the original Kronos and solidified the MB and connectors on the K2.

[Derek Cook]

Thanks for the detailed report, and one to watch out for.

Most keyboard problems (and other electronic systems) I have ever had have been due to tarnished connectors or thermal creep on socketed ICs or connectors (I remember a chip on a micro board in work that had completely worked its way out of the socket it was in (cheap, not turned pin) and was only held in place and working (most of the time) due to gravity!

I guess this is one small drawback of the Kronos using commercial motherboards, which reminds me it is about time I got a spare one for my four year old Kronos "just in case"

[Knave101]

Very Interesting follow up. The repair I made solved much of the problem, and the Korg was running again. However, the piano still crashed today after my keyboardist was pounding on the keys during a song.

So, I looked closely at the photo I submitted above and I noticed that pin 4 seems not to be in line with the other 3.....

sure enough. I opened the keyboard and indeed pin 4 was broken just like pin 5. So I am sure this must be a very common problem in these early Korg Kronos.

I soldering in a wire in place for this and testing will commence tomorrow. So if your keyboard has the sound of a loose screw rolling around....it comes from the motherboard...and this stresses this wire connector.

[Knave101]

I finally solved the mystery of EXACTLY why this Standoff board pinout broke. First, the KLM-3008 is located directly beneath the metal keyboard. Therefore, when both screws on the Motherboard fell out, the board flexed downward. This is made worse with transport and during actual playing when pounding on the keys...flexing the entire keyboard. The mother board was caught during it's downward flex when the connector on KLM-3008 hit the actual metal portion of the keyboard. It only catches by a couple millimeter....but it's enough. This eventually caused the pin connector to flex repeatedly and enough to fatigue and crack two of the pins.

Note that my Kronos is an early model....serial number below 3500 and has the Intel D510 motherboard. This may not be a problem in newer models.

The motherboard screw in the photo, is critical, and in my case...was gone.

[img

Thus, the critical part of the failure is the loss of the two MB screws on the same side of the board, allowing the 3008 board to contact the keyboard at the pin connector....eventually breaking some of the pins.

You think Korg would make this part easy to purchase, but no. I sent the MB type, the serial number to the Korg parts store, and they recommended a different part...nice.

[/img]

[matro]

You think Korg would make this part easy to purchase, but no. I sent the MB type, the serial number to the Korg parts store, and they recommended a different part...nice.
[/img]

It seems like they decided not to continue supporting the D510mo-based models. All spare parts are for D525mw, that actually started being mounted even before Kronos X got released.
Mine have lower serial number than yours. I plan to replace the D510. But you need 3 Korg parts besides the motherboard:
- New version of KLM-3008
- New cables from the powersupply
- Some new chassi-part

[Knave101]

Played again last night and the Kronos crapped out.....for a different reason.

Was noticing that when the keyboardist pounced hard on the keys and the kick drum was vibrating the floor the Kronos would crash. You could see a subtle shimmer of white across the screen when you hit the Kronos on the left most aspect (above the MB). It eventually crashed, and would not come up.

The boot would proceed until the RED line hit the "S" in Kronos, then throw a message to restart. A quick surgery on the stage yielded the RAM end's coming back. Pushed the RAM in and clicked the endpieces….and we were back up and running without any issues for the entire show.

It seems to never end. I guess desktop computers with a keyboard attached were never meant for the perils of transport and dynamic stage conditions.

But it did have a good ending eventually. The Kronos is back up and running now.

[Knave101]

You think Korg would make this part easy to purchase, but no. I sent the MB type, the serial number to the Korg parts store, and they recommended a different part...nice.
[/img]

It seems like they decided not to continue supporting the D510mo-based models. All spare parts are for D525mw, that actually started being mounted even before Kronos X got released.
Mine have lower serial number than yours. I plan to replace the D510. But you need 3 Korg parts besides the motherboard:
- New version of KLM-3008
- New cables from the powersupply
- Some new chassi-part

Let me know how this goes. My question regarding changing a MB is the BIOS, and is it as simple as changing the board and associated parts? Because it would be nice if there was an "Upgrade Kit" available, with all the parts, and downloads to get the units upgraded.

[matro]

You think Korg would make this part easy to purchase, but no. I sent the MB type, the serial number to the Korg parts store, and they recommended a different part...nice.
[/img]

It seems like they decided not to continue supporting the D510mo-based models. All spare parts are for D525mw, that actually started being mounted even before Kronos X got released.
Mine have lower serial number than yours. I plan to replace the D510. But you need 3 Korg parts besides the motherboard:
- New version of KLM-3008
- New cables from the powersupply
- Some new chassi-part

Let me know how this goes. My question regarding changing a MB is the BIOS, and is it as simple as changing the board and associated parts? Because it would be nice if there was an "Upgrade Kit" available, with all the parts, and downloads to get the units upgraded.

You are not suppose to do that yourself. There is a Kronos (X) service manual floating around somewhere on the internet.
There are also some threads here on the topic on changing MB:
http://www.korgforums.com/forum/phpBB2/ ... 0&start=15
http://www.korgforums.com/forum/phpBB2/ ... 36d4da9fb6

[Falcon2e]

Well, after reading this great post, my question is, should I get inside my three year old K2 (that works great) and check for possible loose screws on the MB? I like the idea that ‘if it works, don’t fix it’. What would you do?

[geoelectro]

I bought my first K61 in 2013. It had a loose MB screw. I carried it to church every week and a screw came loose a second time. So I was opening it every year, tightening screws and cleaning it out. Last year I bought a second K61 (K2). It had a loose screw right out of the box. Now both boards never move so I no longer worry about them.

If I ever open one again I will likely add some thread lock to the MB screws.

Geo