I don't know if this is the right forum, but I have 3 out of my 5 Raymarine displays whose display brightness at 100% displays as if it is 10%. I thought these displays model number was ??60, But when I search Raymarine, it looks like their replacement is an I70. Is there anything I can do to increase the display brightness?
There are electronic repair shops that may be able to replace the LCD screen, just a bit of persistence required to track one down in your local area. I had good success with a Yanmar B panel, a Toyota Landcruiser instrument display, a mobile phone etc they were way cheaper than a replacement.
ST60 LCD's are still available, check on ebay regularly. There are other sources in the UK. It is an easy replace no soldering required just careful handling. It is unusual for the displays to fade as described it is less unusual for them to suffer burn out (blackening).