I experience exactly the same on the new Sony VAIO Pro. Fn+F5 and FN+F6 work after each reboot. Then after some cycles of sleep and resume, they no longer actually change the brightness despite that the on-screen brightness bar moves. I've reloaded the right video driver and made sure all settings of "auto brightness" are turned OFF. No help.
Hi nivkagan. I understand that your function keys (FN) are working when you said that the buttons are working. Do you have the correct video driver installed from our esupport website?
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RichO, it is not the driver, but something in the BIOS or Windows system that stops working after a sleep of the laptop. I found a short sleep does not affect but putting the laptop in the sleep mode over a night will render the brightness adjustment useless.
Sorry for the delay. As for the brightness issue, please bear with us as Sony Eng is working on resolving this issue as we speak. Once they have a resolution, it will be posted at esupport.sony.com. So please check regularly.
I also have the same problem with my new notebook.. I bought 2-3 weeks ago and faced with several issues... PLEASE HELP ME!!... since the brightness doesn't change the battery gone in a very short time. My laptop is vaio svf152a29w Mehmet