Sadly your system uses CCFL's which over time do fade in brightness as they get close to burning out.
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Sadly your system uses CCFL's which over time do fade in brightness as they get close to burning out. Just like your office ceiling CFL's do.
While you can still get replacement CCFL's they are a bear to replace and if you're not careful easy to break as well. Here's a good guide to follow: [guide|5865|Removing CCFL from iMac 20in LCD CCFL assembly]. If you've never attempted anything this complex you might want to opt out and just replace the complete LCD unit. While more expensive it is a lot less work and risk. Here's the IFIXIT guide: [guide|998|iMac Intel 20" EMC 2133 and 2210 Display Panel Replacement].
Sorry I missed this the first time :-(
Sadly your system uses CCFL's which over time do fade in brightness as they get close to burning out.
While you can still get replacement CCFL's they are a bear to replace and if you're not careful easy to break as well. Here's a good guide to follow: [guide|5865|Removing CCFL from iMac 20in LCD CCFL assembly]. If you've never attempted anything this complex you might want to opt out and just replace the complete LCD unit. While more expensive it is a lot less work and risk. Here's the IFIXIT guide: [guide|998|iMac Intel 20" EMC 2133 and 2210 Display Panel Replacement].