Problem with ambilight LEDs at 47pfl6877

[ni_hao]

I recently bought a 47pfl6877k/12. I only use the TV with my HD sattelite receiver so no antenna cable connected to the TV.

My problem is that at the back of the TV are 3 rows with (ambilight) LEDs: left, right and at the top.
Direct after installing the TV all three rows with (ambilight) LEDs where working properly. Then I configured the TV for personal use (with ambilight activated of course) and upgrade the software to QF1EU-0.150.48.13.

Now when I use the TV I only see the (ambilight) LEDs at the right burning. So the the LEDs at the top and at the left (back)side are off. I tried several things: factory reset, switching/powering off the TV, but unfortunately.

Question is: how to get ALL the ambilight LEDs burning again when using the TV?

Is this a software bug?

Later:
for some reason I can not update the firmware with the online software update feature (no new releases found). So unfortunately I had to update the firmware by using a USB stick. I now have I updated the firmware by using an USB Stick so my current firwmare is now QF1EU-0.150.82.0. Problem with ambilight LEDs is not solved so it still exists.