how can i fix my lg 32lc46-zc lcd tv?

LG 32LC46-ZC TV. Audio problem.
Audio on scart and analogue inputs, but no Audio on HDMI slots. I have used several different input devices and cables to narrow down the fault location. It is in the TV.
I have done a factory reset on the TV to eliminate any setup changes I have made.
During the language setup the sound returns on the HDMI inputs. As soon as the analogue and digital channels have finished searching and I select one on the HDMI inputs the sound has gone again.
The inputs I am using are a DVD player that has a HDMI output and a Laptop with HMDI output. I have had HDMI audio before from both these inputs on this TV.