Modify K750 cable working without ext power.

[Falck]

Hi
As requested from Zulea im here posting howto make K750 4 in 1 USB cable adapter work WITHOUT external 3V power supply.

1. Open K750 phone connector.
2. Cut red and black crocodile wires off and pull out of connector.
3. Remove black crimp around red wire from cable.
4. Solder now this pin (PIN 10 - CTMS - red wire from cable) with the pin where you cutted of red crocodile wire (PIN 8 - VPPFLASH) together.

WBR Falck

Edit: I just edit text to be more clear, and attached new picture. Zulea.

[Falck]

And then result. After cable connect done without touching phone at all. Easy as h***

WBR Falck

[Falck]

Originally Posted by wenka

You hates forgotten to write it from Benny, handy style, is

Hehe, thats true with all respect, THX goes to Benny, he posted this at gsmfreeboard.

WBR Falck

[Die 1973]

Great!!!!!! Thanks for that tip!! Works like a dream




// Die 1973

[defuct_k]

and is it possible to use without the cruiser 4 in 1 cable? just a simple usb or data cable (RS232) ?

[e2nak]

@ Falck

as per ur instruction and picture i see that the vppflash 3v is to be connected to red wire ctms/rx pin no.10. and that red is not power from phone battery. need some clarification on pin outs. so it means that the vppflash and ctms/rx are to be tied together... as per pinout battery power is at pin 11...

[Falck]

Originally Posted by e2nak

@ Falck

as per ur instruction and picture i see that the vppflash 3v is to be connected to red wire ctms/rx pin no.10. and that red is not power from phone battery. need some clarification on pin outs. so it means that the vppflash and ctms/rx are to be tied together... as per pinout battery power is at pin 11...

U are right, i must admit i have just read and translated post from benny77 at freegsmboard to share these usefull informations without checking it. Have now tested, its correct that pin no 8 vppflash are to be tied together with pin no 10 CTMS/rx(computer to mobile station) and this line is not power from phone battery but i dont agree with with u about pin no 11 CFMS/rx (computer from mobile station) is power from phone battery either. BTW the voltage is now 3.3V into vppflash.

Have now edited my first post about phone battery

WBR Falck

[Ron2pet]

and it works also in flashing.....


Switch phone ON
Get phone info
Phone OTP CID: 36
Phone Flash CID: 36
Phone KEY: A1_DB2010_36_RED
Phone IMEI: xxxxxxxxxxxxxx
Flash ID: 200D
Switch phone ON
Send FLASH application
Send MAIN flash file: "K750_R1K001_EAL_HONGKONG.mbn"
MAIN flash sent OK
Send FS flash file: "K750_R1K001_EAL_HONGKONG.fbn"
FS flash sent OK
Operation succesfull


Best Regards,


Ron2pet

[SR-sigma]

thank for advice Falck

[e2nak]

@ faclk

sorry typographical error battery power is at pin 12 not 11 stand corrected.

regards.....

[luskao]

Can someone put a draw schematic for do a complete K750 cable??Because I can see really well on falck's pic.

Thanks in advance

BR

[crusher]

hey man, this is crap at all.
this "works well" till one time the phone UART won't stand the current the flash erasing draws from it, and loses communication with the DCE forever.

rather connect the pin DCIO with 2 diodes in series to the VPPFLASH as follows:

DCIO --->|---->|--- VPPFLASH

WARNING: if you use Dummy Battery or external 5V from "R&D LOL cable", you must use 4 diodes, not 2! You should measure the power on the devices, with the principle that each diode drops 0.5V of voltage (not depending on flowing current).

* Best diode is 1N4148 for this reason (it is cheap as hell )

[zulea]

Originally Posted by crusher

hey man, this is crap at all.
this "works well" till one time the phone UART won't stand the current the flash erasing draws from it, and loses communication with the DCE forever.

rather connect the pin DCIO with 2 diodes in series to the VPPFLASH as follows:

DCIO --->|---->|--- VPPFLASH

WARNING: if you use Dummy Battery or external 5V from "R&D LOL cable", you must use 4 diodes, not 2! You should measure the power on the devices, with the principle that each diode drops 0.5V of voltage (not depending on flowing current).

* Best diode is 1N4148 for this reason (it is cheap as hell )

1. - this modification IS TESTED BY MYSELF !!! and working WELL and I have used MANY TIMES flashing K750 and W800 (because in this way I 'collect' new flashes from other tools)
2. - each 1N4148 diode drops EXACTLY 0.6 volts. Just learn little more some electronics.
3 - "should measure power" - in fact should measure VOLTAGE !!! POWER is something TOTALY DIFFERENT ( P = U * I )

So, when you take pills or drugs, beter stay and watch TV and avoid posting on this forum ...

Best regards,
Zulea

[luskao]

Zulea could you post an schema in support area??

BR and many thanks

[zulea]

Originally Posted by luskao

Zulea could you post an schema in support area??

BR and many thanks

Hope this help more:

1. Desolder (or just cut) the 2 "crocodile wires" (red and black)
2. All the other wires who comes from "USB-Cable-Box" let in same positions
3. Solder together the 2 K750 connector pins as shown in photo from Falck (also let there the wire who goes to "USB-Cable-Box")

I made this modification on 2 kind of cables:
- 4 in 1 with PS2 connector (Teleway made)
- 4 in 1 with RJ45 connector (Pinky made)
And on both work well.