This answer applies to R4i Mk2
On R4i the brightness of the display screen in standby is set to low so it can be read in a darkened room but will not disturb sleep. If the OK button on the remote control is pressed whilst in standby, the display will light up to full intensity for a few seconds. This allows the time to be easily read in a bright room without switching R4i on.
If not, please do not hesitate to contact us via our support enquiry form.