(Solved) Lexia appear on USB like “Unknown device”


When connecting lexia 3 interface to the USB port, the card is recognized and detected with USB com board driver. After flash spi flash (Winbond W25Q80B) for changing the serial number and flash MB90F546GS microprocessor with SCARY file for recognition in EVOLUTION driver; the interface is no longer recognized on USB port? After re-reading the SPI flash, this one is empty ???


Missing +Vcc on the pull-up resistor 3.9 Kohms, inner track probably cut …

Setting up a wire to bring the +Vcc on the pull-up resistor.

lexia3 pcb-01

lexia3 pcb-02

Trouble shooting Description:

After changing many components, among other SPI flash, HA86, Micro MB90F546GS … etc, I have come to think of a concern for missing pull up resistor or a problem on a layer track internal …

Indeed, the return signal for communication between pin 2 (DO: data output) of the spi flash W25Q80B and pin 28 (P50 / SIN2: Serial data input) of the microprocessor MB90F546GS fact it through two logic circuits: a ACHT86 and HB125; in order to change the logic state and complicate the task of reverse engineering.


Hoping that this could be used for other …

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