Information provided here may cause your phone to malfunction. Modifying the software of your GSM Phone is only a personal choice and shown for amateur purposes only. Commercial attempts based on these hardware and software may be possibly illegal. So take the risk yourself.
Although new phones are protected against such kind of attempts, It managed to enable permanent test mode and keypad code entry feature on my V3690. Thus it became possible to enable Engineering Field Options menu and others through the keypad of the phone. But unfortunately SP-Lock could not be removed. It found some software/hardware promising this can be done on the web, but either their software or hardware were missing in their ZIP files. So the following instructions are only covers the modifications done successfully. Again, these are provided for informational purposes and personal amateur use only. You are taking the risk yourself. Tweaking a memory content may cause the phone malfunction, which may only be recovered at a qualified service, and even an electrical problem (such as a short circuit, wrong connection or surge voltage) may lead to an unrecoverable failure requiring a part change
Interface circuit consists of three transistors and six resistors and so simple to build. It prevents direct connection of the TTL interfaces of both computer and the phone. Computer’s serial COM1 port (usually where a serial mouse is connected to) is used to connect interface with a female connector. Phone’s SIM socket is where the other end of the interface is connected to. A small SIM adapter is used to ease this. It’s a PCB board cut as the size of a regular SIM module and contact points are etched on the copper side of it. I’ve used it as is on V3690 and V2288 and placed in it’s credit card size SIM Card frame to be inserted in d460. Since the cables won’t fit in, I had to open the d460 and fix the card manually inside it.
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