Korg Forums

Respectfully, might it not be wiser to simply send the Kronos in for repair at this point?

McHale , before some weeks I wrote you the following

In order to test Enhance ENO-1612 (outside Kronos) , plug in 90-300 Volts AC in input , ground green cable (PS-on)
and then check all voltage outputs as described in bellow technical sheet , page 2.
http://www.enhanceusa.com/upload/DM/201310030839530.pdf

If you hadn't test it then do it know but do not disconnect anything !
Just cut green cable that returns to GPU and ground it (in GPU side) !
This will enable Enhance ENO-1612 voltage outputs to active and supply motherboard for further operation !
Let us know for your actions !

Both times I tested, it was installed IN the Kronos, fully connected. Had the power supply fixed the issue, all I'd have needed to do is replace the screws on the bottom.

This seems really weird !
Be sure that main switch closes circuit , and as connected to mobo , ground green cable and try to connect a dummy load
at +12 V (see PDF) , using alligator clips , like a car lamp around 20-50 Watts !
- If lamp will light up normally , then GPU is fine , and if meantime fan or screen still do nothing then some motherboard
switching MosFet transistors might have been burned in ... in that case bad news , you have to visit an official repair center
since this step requires experience and knowledge to try it yourself !

Well,

Just bypassed the on/off switch and hard wired the PSU directly to the wall. NO change. According to Dan, the display and fans should switch on. I haven't tried putting a 12v dummy load yet. I'm tracing wires pinouts and wiring now.

Damn.

Thanks for the help AntonySharmman.

-Mc

You're welcome ...
The reason that you have to connect a power dummy load , is because just only a voltage meter counts floating
current of 12/3.3/5 V and when current increases maybe SMPS lowers the voltage outputs , which is an infinitive loop
for motherboard power logic switches that will never enable CPU and terminals !

Keep also in mind that PSU has short circuit protection and in case of any , you will hear a "sparkle" type sound
of approximately 8 Hertz coming from PSU 'cause of extremely high Electromotive Force of protection circuit chirp pulses.
This could be the worst scenario in your case , since somewhere there could be a short circuit that prevents PSU
to feed your device !

New motherboard ordered. Let's see if THIS fixes it.

I guess I have a spare power supply in the event the original fails unless someone needs one in the meantime.

-Mc

duplicate msg.. sorry.

McHale,
I've had a very similar situation as you. very little use in the last 2 years of ownership and suddenly it dies. My issue is a little different in that it will start the boot up process and then die completely without an error message -occasionally it will boot up and I can play it for 5-10 minutes before it dies unexpectedly and completely- it feels very much like a PSU issue...

Also, my assistance with Korg support has been abysmal, and my local (1.5 hours away) repair center won't return my calls.

I'd love to have them ship me new parts, as I am quite capable of doing repairs myself... Please keep us up to date on your issue. I've felt all the same things you've written!

mattaniah
Your issue is definitely GPU Enhance ENO-1612 , this was exactly the symptom I had before 2 years and replaced
it with no second thought !
So ask McHale to ship you his spare one if you feel that you can replace it !
In this topic you can find all needed information for that !

Thanks Antony,
do you know if there's an upgrade to the GPU so that this will be less likely to occur?
For instance I built a computer 3 years ago and it's been in all kinds of conditions and has been left on for weeks at a time, but keeps chugging along without a problem. Why should my (much more expensive Kronos) be any different?

If you're a technician you could follow alternative option like picoPSU-120 , that also discussed here
http://www.korgforums.com/forum/phpBB2/ ... c&start=60

McHale I am sorry you still don't have your keyboard up and running. I hope the motherboard fixes your instrument. I did buy an extra motherboard at the time I purchased the Kronos, just in case. I like the alternative to the power supply that is posted here. I would follow those instruction if I had a power supply issue. My instrument works fine but I don't use it very much. It does sit for months at a time unplugged. I hope I don't experience a problem as you have. I think if this keyboard is to have any longevity it will only be through the troubleshooting and maintenance done by the owners. The best of luck getting your board up and running.

lonelagranger wrote:I think if this keyboard is to have any longevity it will only be through the troubleshooting and maintenance done by the owners. The best of luck getting your board up and running.

Thanks! The main reason for this long, drawn out post is to have a repository for the troubleshooting since electronics fail and people will need to troubleshoot their own problems down the road. My motherboard came in on Saturday and I'll try to install it tonight. I'll report back either way. If that fixes the issue, the next step is to see what happened to the old one to get it up and running as a spare. Theoretically we're just working on computers with a bunch of attachments.

-Mc

Fingers crossed for you!