A bit confuse here
1st, you say the communication is OK, which part of communication is OK? because PSC28A is standalone with straight output from PS2, no communication like SKPS where host need to communicate with it via UART.
Which LED are you referring to when you say it is not light up. Are you referring to STATUS LED, the super bright blue LED? Or the small red LED as the output indicator? Or the small green LED as power indicator?
PSC28A come with a few simple indication:
1. When there is no PS2 connected and PSC28A is powered up, the SB (Super Bright) Blue LED will blink with slow rate, dim and bright is slow rate. This indicate that controller on PSC28A is running and working. If at this stage, the SB Blue LED is not blinking, mostly the cause will be the power or controller on PSC28A have problem.
2. When there is PS2 connected properly and PSC28A can detect the PS2, the SB Blue LED will stop blinking, and remain at a certain brightness, around 30% of brightness. So if in this condition, the SB Blue LED is still blinking at no.1, most likely the PS2 is having problem. You can verify with another PS2 if you have as suggested by Allen.
3. OK, let's assume the SB Blue LED stop blinking and remain it brightness. Pressing any digital button on PS2 will make an output to small red LED and the SB blue LED should illuminate with full brightness to indicate that there is at least 1 digital button on PS2 is press.
If you still have problem, you can fill in the form under support tab under our website as suggested by robosang. Our technical team will follow up with you.