After going home i take the multimeter it is a PROSKit MT 1706 and start reading again and again on forums so I decide to teardown it and make an analysis of data stored in eeprom and hack it EEprom from originaly dump appears like this
we see on its dump no thing extra or strange so i decide to make an excel file to analyse data stored in eeprom
i take an hexa from editer and past it on data in excel and i see the max range , and all data relative to manufactor
I take my old programmer type CH341A and its onboard IC clamp, after more reprise it didnt success reading then i went to solder on PCB
and starting reading and modifing data function from 01H to 40H like we see on my older post there is function above 30H
and the result is
RANGE Code Func position Hex
---------------------------------------
600 mVDC 01 08 03
60 VAC 0A 08 09
600 VAC 0B 08 0A
750 VAC 0C 08 0C
60 mA DC 29 08 0E 0F mA DC AUTO 11
600 mA DC 2A 08 0F
60K OHM 17 09 09
600 OHM 15 09 0B
NCV 22 08 05
6 VAC 09 08 08H
Live 24 08 0D
Hz 1D 8 0F
Cont 14 8 1C
1000VDC 06 9 00
600 VDC 05 9 01
60 VDC 04 9 02
60 A DC 2E 9 03
6 VDC 03 9 04
60 A AC 30 9 05
600mA AC 2C 9 06
6 M OHMS 19 9 07
600KOHMS 18 9 08
6K OMM 16 9 0A
° C 1F 9 0D
Hfe 21 9 0E
Diode 13 9 1C
600 mVAC 08 07 AUTO 33
60MOHM 1A
600MOHMS 1B
Cap 1C
% 1E
°F 20
600 uA DC 25 0D µADC AUTO
6 mA DC 26
600 uA AC 27 0E µA AC AUTO
6 mA AC 28
60 mA AC 2B 10 mA AC AUTO
6 A DC 2D 11 A DC AUTO
6 A AC 2F 12 A AC AUTO 36
60 uA DC 31
60 uA AC
INFO the function is mentioned in right is the same range in AUTO mode after this i change max range to 9999 count and over range OL is 10000
after this i try to add some button like REL/RS232 and other but nothing hapened when switching.
I think for automatic ranging there is something added on data in the header of eeprom
Example : we see
it not described on DTM0660 datasheet
so i add on some range the same range in automode but i discover only Amper range can be in auto mode ( no volt no Ohms )
here is structure of 80h and BFh
0x80H 00 00 24 01 00 22 1a 19 09 0a 0b 21 0c 31 29 2a 06 05 04 2e 03 30 2c 2b 18 17 16 15 14 1f 1c 1d
0xA0H 00 00 00 07 00 00 00 00 00 00 00 00 00 0d 0f 00 00 00 00 00 00 00 00 10 00 00 00 00 13 20 00 1e
I have added
600mvAC on 600mvDC (not modified but ADDED)
60mADC AUTO on 60 mA DC
60mADC AUTO on 60 mA DC
600µADC AUTO on 60µA DC
that's all
any other idea ? or suggestions ?
dumps of orginal and modified