It took a while to find the solution. Not sure why this is a super secret ... To rest to factory i did following and it worked for me:
1) On display panel there is a button to go back (it is the first up from bottom ). It will be visible when you select from menu and sub menu as network setting.
2) Just visually remember where it is located. press it 5 times.
3) it will take you to different screen, with function shown on top line in display.
4) scroll until you find setup or customer support.
5) select that and go down in the list , you will find semi-full factory reset.
6) select that and you are done.
There are lot of service agencies out there who want to charge for this. If you get stuck let me know I will walk you through. I do not want money, if I could save someone the time I spent in finding this solution, is the biggest gift !!!
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