Electricity disrupted, reset buttons will not respond

Try unplugging the unit for 5 minutes and see if it resets, if no joy you have a possible burnt control board due to a power surge.

One simple thing you can try is to unplug the electrical cord from the wall for at least a minute then plug it back in and try the machine. This worked for me recently on an LG front loader that I was asked to look at. The machine wouldn't respond until I reset it then it worked fine.

You disrupted the flow of events and cause confusion. Reset and start over.

all buttons of my kenwook dpx 4020 does not respond. I tried to press the reset button but that does not respond too

Two-element water heater is 240Volts.
No hot water means: ECO reset button tripped, upper element bad, upper thermostat bad, or 240Volts is not reaching water heater.
Circuit breaker can be delivering power on one leg of the 240V circuit, so water heater appears to have electricity but is only receiving 120V.
Test for 240volts across top two screws on upper thermostat.
Look for loose wires and burned connections.
Push in reset button real hard.
Replace both upper and lower thermostats.
Remove wires and test upper element for continuity.

Open following links for do-it-yourself troubleshoot walk-thru:
http://waterheatertimer.org/B220C.html
http://waterheatertimer.org/How-to-replace-thermostat-on-electric-water-heater.html
http://waterheatertimer.org/How-to-troubleshoot-electric-water-heater.html
http://waterheatertimer.org/Test-electricity-to-water-heater.html

The cancel secure button has a lock-out feature. Hold the button until the off indicator disappears.

The reset button kicks out because the thermostat detects overheating.
Anything over 150 degrees, the reset kicks out.

This is caused by 4 things.
1) Bad upper or lower thermostat. Thermostat sticking in 'on' position and elements overheating water.
2) Factory-installed insulation and cover are removed
3) Bad element shorted to ground at center of element, and element continues heating with 120V through the ground wire.
4) Loose wire near upper thermostat, that is shorting and causing heat.
http://waterheatertimer.org/How-to-troubleshoot-electric-problems-with-water-heater.html

Solution:
Check for missing insulation.
Check for loose and burned wires.
Replace both upper and lower thermostat.
http://waterheatertimer.org/How-to-replace-thermostat-on-electric-water-heater.html

If problems continue, test water heater elements and replace bad element.
http://waterheatertimer.org/How-to-test-water-heater-element.html

If you need more help, add a comment and I will respond.

Hi cschnur,
     It seems that you might need to replace circuit board.
All the above mentioned conditions refers to a faulty circuit board. You might have blown few Ic's.
Take a voltmeter, check the continuity. If you are aware of the Ic's, replace them.
Unless, look for a tech, a used board ( On http;//www.ebay.com ) or purchase a new one.

Thanks for using Fixya.
Do rate the solution as "Fixya" if 100% satisfied.

Your power company has a free service whereby they will come to your home after a power failure and check things out for you. I would begin by calling them. It is possible that you have a problem in your electrical panel which is limiting the power to one side. Call them and let me know.

You may have the dreaded F7 problem. Go to the following link:

http://www.fixya.com/howto/h155060-dreaded_f7_error

Please let me know if this works for you. I have shared this fix with over 1600 folks and most report success. You can email me at [email protected]

Regards,
Charlie Popeck, P.E.
Consulting Engineer