2006 iMac 17” Model A1208 - screen won’t stay on

Two possibilities come to mind:

1. 1. The display is dead.
   2. The PRAM battery is dead.

Hard to say what you should do. There haven't been new parts made for that model since around 2014 meaning they may be hard to find. Apple will not do repairs on obsolete models, so you would need to find someone with repair experience on Macs to check it out and/or repair it, if repair is feasible.

I hate to tell you, but the 2006 iMac had a lot of hardware issues from bulging/leaking capacitors on the Logic Board and Power Supply to defective LCD panels. These computers are very hard to open up since the release levers for the front cover are very difficult to access so replacing/removing the PRAM battery is not easy.

[Edited by Moderator]

I bought one of those new and it wasn't to bad. It was rock solid for about 6 years and then the display started getting pixelated lines. So I opened it up, disconnected the internal display and installed a 500GB WD HD, set a 21.5" LG display in front of it and plugging that into the mini DVI port, then I used it that way for several more years. I considered myself one of the lucky ones, because some of those Early Core Duo's had Display and SuperDrive issues within the first year.

I have two in my family that still work like new! (except maybe the dvd drive)

As a matter of fact just a few days ago I reloaded Snow Leopard 10.6.3 on one and created a dual boot SSD w that and Lion 10.7.5 in separate partitions.

🤯

edit - Why? Just because. 😄

Just get a new computer

Sad to say, the late 2004 to late 2006 iMacs were the worst ever. :(