Here a few tips for assembling AllPro adapter:

• The IC2 & IC3 are SMD chips mounted on the solder-side and the white dots on the chips are corresponding to the white dots on the PCB.
• Pay attention for soldering SMD parts. Make sure the ICs are flat against the PCB as possible. This will help prevent open disconnects. Sometimes the PCB finish is not providing good adhesion. Inspect the soldering afterward. Use solder wick to remove solder between pins.
• The component placing for the top and bottom sides is shown below:

MOSFET P-channel transistors pinning is confusing. The original Philips BS250 got the TO-92 variant A when Vishay Semiconductor's TP0610 and Supertex VP2106 are TO-92 variant B. The PCB white silkscreen marking for Q2 transistor is corresponding to variant A. If you got variant B rotate it on 180 degree during mounting. You can use ohmmeter the check the polarity of transistor internal protection diode to figure out the right polarity, as shown in picture below..

Testing the adapter assembly

It is recommended to test the adapter assembly before connecting to the vehicle. Get the 12V DC power supply connected to Pin 1 and 9 of DB9-M connector. Start Windows Hyperterm, connect to the serial port used by adapter, the COM port parameters like parity, speed do not matter as it is a virtual serial port anyway. The communication protocol is text-based with modem-like "AT" control sequences. The adapter command "AT#3" is performing self-diagnostic test, see picture below.