Hello,
Thanks for your reply. Keyboard was not in service, anymore. What I can do, to find source of problem by myself?
Regards,

Pedja.

....Jean sent them a mail about my problem, and technician from service called me. His advice was to bought a set of new cables and change them....

I would do this.

Hello Wildbill,
Thanks for your reply. Did you have some similar experience (with OS restarting) with your instrument?

Hello Wildbill,
Thanks for your reply. Do have some similar experience (with OS restarting) with your instrument?

No.
But I did have some problems with the usb on my le6.
Took it apart and some of the wires looked really flimsy and loose, so I wouldn't be surprised if it was a simple wire problem. A loose connection is enough to cause an intermittent problem.
Maybe not something you would try to fix yourself.

Wildbill,
Thank you very much, for your very clever suggestion, I really appreciate it. I have some problems to bring keyboard to service, but maybe it is a best way to do it so. Thank you very much again, and I wish you all best.
Regards,

Pedja.

Sadly,

I have to say that I have again experience with restarting. I formed a rule, after two years of repetitions in same period (May or June), when humidity rise outside and in the room. That problem lay in capacitors. I don't have time now, to check this (with service men):

https://jirin.web.althan.cz/201705-kurzweil-pc3le-blinking-problem-ultimate-solution/

But, I will finally have to do it.  

Again, last days I had a same issue. One restarting during playing. Two times in few days!

Hi,

I think you need to take that keyboard to service.

Regards,

Fran

Hello Fran,

I hope that you are healthy and good, this very bad days.

Thank you for suggestion,

Pedja.

After a 7-month break, I faced three restarts again, last night. 
I have the impression, although I may be wrong, that the reason for this may be the use of a certain combi on Kronos. 
Since I use PC3LE8 as a keyboard controller for Kronos.
Thanks for your attention.

Few months I didn't play PC3LE and last night I unpleasant experience.

This time, the restart started after five minutes of playing, and it went into a loop of restarting several times. After that it behaved normally. A similar thing happened to me, a few days ago, but with pauses between restarts.
I was doing a test today, I turned it on and let it run for two hours. I didn't play the whole time, but I did a few times during that time. The instrument behaved completely normally. I try to avoid the service, because I don't really trust their training. However, if the whole thing continues at this rate, I will have to.

Hi,

While restarting could be for several reasons, on the PC3LE the most likely scenario is a hardware issue that CAN be fixed if the service center is official and get the proper details from Kurzweil HQ. Once that is done, no more restarts due to that.

Regards,

Fran

Thanks hipogrito,

You are always here to help.

Service Centre for Kurzweil instruments doesn't exist in Serbia.

Theay are not specialist for Kurzweil, they work all keyboards.

With PC3LE is special fabric hardware error, with capacitor.

Capacitor error. I'm afraid to do it myself, but even more to leave it to them.

Their theory is based on the connection of flat cables and their replacement.

I would not say that, because the instrument does not moved and it is in exceptional conditions of protection from dust.

That's why I hesitated so long (with service).

Thanks for all your attention.