Philips lcd 42PFL5522D Backlight Clicking ?

[buncey]

morning everyone.

i have a philips 42PFL5522D in workshop.

set suffers from a weired problem when you first switch the tv on you can hear a type of clicking noise for about 2 mins.

also when you switch the tv off you can hear the clicking noise again for about 2 mins?


checked power board the clicking is not comming from psu but seems to be comming from i think the backlights as the sound is comming from middle of set behind metal cover. the sound is quite loud which i can only describe as its like somethink is clicking on the metal chassis.

i have noticed this problem on 2 identical model sets.

anyone have any ideas or come across this problem before on this chassis?

thanks