Hi,
when I connect the card to USB port, only LD9 is on; LD11 (Power) not.
Where could be the problem?
Thanks a lot,
Bejdzan
The LD9 should not be lit.
Have you checked the right polarity and connection of LD11 ?
The LD11 is directly connected to the USB +5V via R18.
It should be lit when the USB cable is connected to PC.
Most likely there is an assembly error.
Can you provide links to sharp and high-res pics of your assembly (both solder- and componentside) so that we can have a look and maybe provide some feedback.
Thanks for replay 
After resoldering of USB connector LD11 is Ok, but LD9 is still on immediately after connecting to computer.
Where can I send the pictures?
Thanks
Is the K8055N card detected by the PC?
Does there appear new device under the ‘Human Interface Devices’ in the Device Manager when the the K8055N is connected to PC?
[quote]Where can I send the pictures?[/quote]You can upload pictures to a free image hosting service and post links here.
It does nothing 
Here are links:
dropbox.com/s/px71t1xr40zdv … 5.jpg?dl=0
dropbox.com/s/mmkf5uu9lelb5 … 3.jpg?dl=0
Thank you for the good pictures.
Soldering and the assembly looks very good.
If you have a multimeter, please check the voltage on pins 1, 9, 10, 12, 13 and 14 of IC3.
You can use any GND terminal of the screw connectors as ground reference.
The voltages should be about:
1: 3.3V
9: 1V
10: 1.4V
12: 0V
13: 0V
14: 3.3V
The voltages are:
1: 2,5 V
9: 0,1 V
10: 0,7V
12: 1,1 V
13: 2,9 V
14: 3,3 V
Please check the ground connection of pin 19 of IC3.
There should be 0V on pin 19.
Please check also voltage on pin 28.
There should be 0V too.
Both voltages are 0V
You can return the K8055N for inspection/repair to your local Velleman dealer or direct to:
Velleman Projects Tech. Dept.
Legen Heirweg 33
9890 Gavere
Belgium