Pololu Serial 16 servo controller doesnt work

Hello there,
I have problems with my 16 servo serial controller. I have assembled/soldered it very carefully.
Whenever I connect my power source (8V) to the controller, the yellow LED burns. I can then attach a servo power source (5V) and attach servos and they get an initial move right when I plug them in. That’s all.
After assembling, I grounded the serial port and connected a power source. But not all LEDs were lighted. Everything just lights the Yellow LED.
I can also connect it to my PC and run this Visual Basic script - nothing happens, the servos don’t move and there is always just the Yellow LED that keeps burning all the time.
It happend 2 times already that the red LED burned and the top green one flashed (wrong baud rate). But it happend only 2 times - it doesn’t happen anymore and I tried all baud rates, the other COM port options were adjusted too. Why does my controller not work?
I grounded myself before assembling and made proper soldering. What could it be? There was one time when I was not exactly sure what to do:
https://www.pololu.com/products/pololu/0240/guide.pdf (see on site 5 on top):

But I think I’ve done it right as seen here (check red arrow):

Like mentioned I soldered very carefully:

I appreciate help a lot. I hope to continue my robot project soon! Thank you very much!

I found out, after reading a lot of stuff on the internet, that I used a wrong RS232 cable. My cable was a random cable from some Networking device.
I’ve seen on the above page that a “robot controller” device needs a straight cable. So I took my old one apart and soldered my own cable, the 16 servo controller device works perfectly. I’ll post inside the projects section, as soon as my robot is built. Thanks for these cool devices!