My Original Kronos Is Dead-Nothing @ Power On.

AntonySharmman · Post by **AntonySharmman** » Fri Jul 26, 2019 1:28 am

voip wrote:... and see if the auto power off option is available .My Kronos X later model has it.

Your Korg arranger have it for sure , Kronos OS had never such an option as generally any computing device
without electronic Power ON/OFF switch !

GregC · Post by **GregC** » Fri Jul 26, 2019 2:03 am

AntonySharmman wrote:
voip wrote:... and see if the auto power off option is available .My Kronos X later model has it.
Your Korg arranger have it for sure , Kronos OS had never such an option as generally any computing device
without electronic Power ON/OFF switch !

I vaguely recall this discussion from 7 or 8 yrs ago. Dan Phillips may have posted.

Something to the effect that Korg had to comply with country rules- where power off feature is a country requirement.

So we have K's with it, some without.

But something tells me that Korg later did something permanent about auto power off at some time.

Sorry, this sounds confusing. Its my recollection and might be off target.

mm-pro · Post by **mm-pro** » Fri Jul 26, 2019 2:56 am

I would never turn it on in any case.

voip · Post by **voip** » Fri Jul 26, 2019 9:25 am

AntonySharmman wrote:
voip wrote:... and see if the auto power off option is available .My Kronos X later model has it.
Your Korg arranger have it for sure , Kronos OS had never such an option as generally any computing device
without electronic Power ON/OFF switch !

Not all Kronos' have it, but on my Kronos X, there is a small motorised pusher on the main power switch that is used to automatically turn off the power. If this has been activated, the switch requires extra force to overcome the mechanism and turn on the Kronos.

In my case, I've disabled auto power off in the Global menu.

.

AntonySharmman · Post by **AntonySharmman** » Fri Jul 26, 2019 10:42 am

voip wrote:Not all Kronos' have it, but on my Kronos X, there is a small motorised pusher on the main power switch that is used to
automatically turn off the power. If this has been activated, the switch requires extra force to overcome the mechanism and turn on the Kronos.
In my case, I've disabled auto power off in the Global menu.

If you're sure about this , I have no reason to doubt since I own only Kronos 1 & 2 , but this function requires for sure hardware components that do not exist in K1 & 2.

On the other hand the existence of a motorized/servo system for such an easy operation is totally insane , this function is always achieved by ST-BY function of
PSU via Mosfet controlled by OS and sometimes like in PaSeries , an extra Electromagnetic Relay is used but in all cases main ON-OFF mechanical switch ,
always override this function , this is the rule in designing such a feature.

NormC · Post by **NormC** » Fri Jul 26, 2019 6:50 pm

My 2015 K2-73 has the auto off power switch.

mm-pro · Post by **mm-pro** » Sat Aug 03, 2019 12:55 pm

Kronos failed again with the new power supply. Not sure what to try next.

GregC · Post by **GregC** » Sat Aug 03, 2019 1:08 pm

mm-pro wrote:Kronos failed again with the new power supply. Not sure what to try next.

I read your 7/25 post above that you fixed your K

?

Is it now DOA ? Or intermittent ?

mm-pro · Post by **mm-pro** » Sat Aug 03, 2019 1:26 pm

Worked fine for a week with the new power supply. I am guessing either there is an intermittent problem and the power supply was fine, or that whatever caused the first power supply to fail has caused a second to fail as well.

mm-pro · Post by **mm-pro** » Sat Aug 03, 2019 1:28 pm

No lights, no fan, no screen. The green light on the motherboard comes on.

GregC · Post by **GregC** » Sat Aug 03, 2019 2:12 pm

mm-pro wrote:No lights, no fan, no screen. The green light on the motherboard comes on.

as you can tell, its guess work here.

Going down the list is mobo, SSD

Getting expensive

qayqaywsx · Post by **qayqaywsx** » Mon Aug 05, 2019 2:20 pm

Hi

DISCLAIMER : BE CAREFUL WITH WORKING ON POWER !!
DONT TOUCH ANYTHING WHICH IS POWERED

you should try to check the voltage of the power connector after switching the kronos on : put the multimeter to V ac switch it on and measure wether there are 230V or 110V (depending on your countries power).

if there is no power there can be many reasons for this behaviour (short circuit dead mb ...)

If i remember the inner things from original kronos right , there is a fuse in the main power cable. Possibly burned ?
Switch defctive ?

good luck

KK · Post by KK » Tue Aug 06, 2019 2:17 am

After this new failure, start with the basics. How stable is the power where you plug your Kronos, do you always use an UPS with it, etc. In one of my older PCs, three or four power supplies toasted one after the other, even though no other computer or appliance in the house ever did. Cause was for some reason it was particularly sensitive to the slightly unequal power in the house. Even if you live in a big city (or not), never assume the electric company gives you clean power. Always plug your unit on an UPS. Basic line filtering is sometimes not enough.

Of course, there could be many other causes as well. An intermittent short can end up damage a power supply. The Kronos is a complex machine and there are also several enable levels/lines controlling the PCBs and main ICs for different purposes. Any one of them can stop everything as a protection. A voltage slightly too high or too low on any of those lines and a whole circuit or more stops waiting for the correct signal. Unless you are at ease with this complicated stuff, I would send it to a qualified tech or Korg recommended service place.

mm-pro · Post by **mm-pro** » Tue Aug 06, 2019 3:58 am

I do use a UPS. I suspect a short. I imagine it will take me some time to find it.

AntonySharmman · Post by **AntonySharmman** » Wed Aug 07, 2019 10:01 am

You might need an expert technician to examine deeper this case or authorized Korg service center !
Kronos Enhance ENO-1612 120W that you have replaced as all PC PSU have a ST-BY input and a ST-BY output voltage of 5V that feeds
mobo ST-BY control stage.
When PSU input voltage goes low (<0.5V) then a mosfet transistor enables PSU and feeds all peripheral circuits including mobo and Kronos boots.
If this PSU ST-BY input voltage is unstable or permanently in low state then PSU do not output any voltage and mobo do not boot !
This SMPS PSU do not suffer by any fluctuation , sparkles or over voltage of net power and has over current protection in summary current flow of outputs.

There are 2 cases of malfunction if there is no any semiconductor short circuit case (that I strongly doubt) :
- PSU has been electrically burned (usually switching mosfets/diodes) with usual initial symptom , burned fuse of PSU board !
- Motherboard ST-BY control output stage is malfunctioning and do not enable control pin of PSU (clear indication by green mobo led)
or has another serious damage and diagnostic logic gates do not allow PSU to power on.

Technician must ground PSU input terminal manually overriding and disconnecting mobo control output and come to a conclusion of the issue there !
My guess , it's the second case , since you have already replaced PSU !

Both cases in nowadays are treated as whole board circuit replacement , very few people have the required knowledge
due to repair the actual failure components.

Good luck