Sound issue on Philips television

Euh... a bit of a silly question... How do you update it?

Re, thank you Tarascon for taking over;-)
Masuké, assuming that you have turned off and then turned on your TV after the update (so that it can take effect) and having nearly the same TV (smaller in size, slightly newer), I don't see anything in the menus that could cause this kind of problem. My opinion (which doesn't pretend to be anything but my opinion) is that I would first try to reset my TV to factory settings, second redo the updates (turning it off and on each time), then make your personal adjustments. If the problem persists despite everything, I only see returning it to customer service.
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"Start by changing within yourself what you want to change around you." M.K. GANDHI

Anyway, on the Philips, there's a hell of a problem with their HDMI ports, whether it's 4 or 5; as soon as you change the source or turn off a recorder or console, it might not restart or it takes 5 minutes after.

Here it is done :)

But still no sound...

Okay thanks, I'll try what you told me and if it doesn't work, I'll tell my dad to return it to customer service.

Hello Masuké, try to update your TV's firmware if you haven't already done so; the latest one is from last August: https://www.philips.fr/c-p/42PFL5604H_12/televiseur-lcd-avec-pixel-plus-hd/aide

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"Start by changing yourself what you want to change around you" M.K. GANDHI