How to solve the problem of data error in casio digital diary sf-3990 128kb

Page 46 of the scanned copy of the manual or near by pages describes an all clear procedure that unfortunately for you deletes all data if the password is unknown.

https://www.manualslib.com/manual/358559/Casio-Sf-4000.html

CASIO SF 4000 Operation Manual

Source: http://imslsoft.com/faq.htm#faq1

What do I need to communicate between my Casio digital diary and my PC?

Most Casio Digital Diary models have a small 2.5mm serial port built into the side of the unit. It can be used to communicate between two Casio Digital Diary units, or with another serial device such as a PC (or a serial printer on some older models).

To connect between two compatible Digital Diary units, you need only a 3-lead crossover cable with a 2.5mm plug on each end, such as Casio's SB-60 or SB-62 cable. You can buy these cables from a Casio accessory supplier such as Windows Link.

To connect to a standard 9 or 25-pin RS232 PC serial port, you need a special Casio-specific adapter cable (more information below). The Casio diary uses its own unique communications protocol, and requires a Casio diary backup program on the PC. You can build your own cable or buy one by mail order, and use it with shareware software such as XLink/Win, or you can buy a kit complete with cable and software such as those sold by Casio or Windows Link

For more information on serial cables, see Cables. For more information on software and kits see What communications packages are available for the Casio digital diary?

For Digital Diary Owners Manuals:
http://support.casio.com/en/manual/manuallist.php?cid=013

OPEN THE BACK AND NEXT TO THE BATERIES THERE IS A "RESET" BUTTON. CLOSE IT AND RE TRY AGAIN

The manual can be downloaded directly from casio.com:
http://world.casio.com/sf/download/en/manual/

You need the exact model number (see the sticker on the bottom of the diary).. like SF-####

Kindly visit the site and download http://www.devicemanuals.com/guide/Digital%20Diary/Casio/Casio-Digital-Diary-SF-4900ER-TVRJMU16Yz.html

forgot password 0 Solutionsforgot password im forgot my password of my casio digital diary sf-4600c 64kb "On" button 1 Solution"On" button The "on" button makes sounds, but won't open my organizer, which is the... "On" button 1 Solutioni am having a much similar problem with an sf5300 it wouldnt turn on so i changed...

http://www.usersmanualguide.com/manuals/casio/SF-6500SY_SF-6700SY_SF-6900SY.pdf

Today i had the same problem with my SF-4900,

the same message apeard did you found a solution to recover the data cauz they are the most importhant
please contact me on this on: [email protected]

read ya,
Gogo

HI,Im sorry i dont know the solution for this..but actually i have the model as your SF-9350 and dont know know how to operate it i mean few thing..plus i have also forgetten my secret password,can you help me out??