How to solve Citroen and Peugeot Lexia 3 PP2000 central locking problem

Vehicle example:
Peugeot 307 2.0 HDi 2005

Diagnostic equipment:
Lexia 3 Peugeot Planet PP2000 for Citroen and Peugeot OBDⅡdiagnostic interface

Problem:
New Pug 307 comes with one original key, so I have to make a new backup key. Got a blank key and got the key cut and programmed with lexia 3 PP2000 diagnostic software. Then I have two new keys that can start the car.

The problem is I can't get the central locking bit to sync (key fob stopped working). At first I doubted the IGN+ position (with engine ON or OFF at the same time). Soon I figured out that I should leave the ignition switch ON without starting the engine.

I got a good key programming document with PP2000 and followed it step by step:
How to program Peugeot new key with Lexia3 PP2000 diagnostic tool

I was stopped at the learning transponder key procedure. I search around Pug forums and finally got the answer.

Solution:
The problem lies on the lexia 3 PCB.

There are different types of PCB on the aftermarket:
1. Original keys which works fine
2. Copy keys sometimes PCB sometimes does not work
3. Second hand keys PCB can not be programmed again

Make sure you get the correct PCB, take this one on uobdii.com
1. Lexia-3 PCB edge is golden with original full chips. Double PCB has 7pcs optocouplers, which are 100% original and new.
2. lexia-3 relays are 12pcs, which are 4.5V, it is more stable.
3. PP2000 has 2pcs Optocouplers.