I am in need of a service manual/circuit diagram for my father's 233Mhz iMac. It seems that the power supply works to some extent; the fan is ok & hd seems to be spinning up, but the green light on the front won't come on & the monitor is dead. Fortunately my dad is a tv tech. He says that there is a voltage problem. It's not putting out the right amount of juice. Problem is, he does not know much about computer power supplies/circuits/what to look for, etc. So, a service manual that stipulates voltages/circuits would be really helpful. I tried: http://home.wanadoo.nl/manual.man/manuals.html#imcs, but their site won't allow dl. Can you post a site that has dl-able service manuals for the iMac - I might even pay for it if there is a reasonable charge. Thanks heaps tk

Could be something as simple as the clock battery is bad. I would replace that first. You have the symptoms of a bad battery, monitor not coming on, hard drive still spinning up. You can download aservice manual here; http://home.earthlink.net/~gamba2/manuals.html

That site redirects to the wanadoo site, which is having problems for the same reason every other site is having problems - Apple has severely restricted access to the service manuals. The analogue board in an iMac is very similar to that in most televisions, so assuming your dad can follow the circuitry reasonably well, he can probably fix any problems by treating it like a TV he's never seen before. Do you normally leave the iMac plugged in when you're not using it, and if so, is it connected to a powered-on power strip when you're not using it? p

common problem with these 233imac are the flyback transformer go bad after about 3 years. I fixed 2~3 of these a week. You can verify by hooking up the mac monitor to the d-15 jack on the imac, if you get the picture then the computer section and the power supply sections are OK. You can get the flyback from nationwide electronics (www.neiparts.net). Battery has no effect on this symtom.

Thank you bob for that link. Downloading service manual right now. I also thought that it linked to wanadoo's site, but it's not. Hope it will help. Thanks also to budum. Dad will check out the flyback transformer. You also mentioned connecting monitor to d15 jack? Can you be a little more specific. Do you mean the power supply that feeds the monitor? Where is the d-15 jack. Would a tv tech know? I have not talked to my father about your recomendations yet. He probably will know what you mean & we will have the service manual. Is the flyback transformer specific to computers or could you use tv parts? thanks tk

it is the d-sub 15-pin connector located on the cpu chassis (right in the middle of the chassis when you remove the bottom cover), it two thumb screws on it. If you have an old mac monitor you will see what I am talking about. I also have the service manual but it does not have any schematic diagram of any circuit boards at all, apple will not supply me one. You will have to get the flyback from the www.neiparts.net, They are my supplier for most of my repair shop mac parts.

"Apple will not supply me [a schematic]" Yeah, because they aren't publicly available, no matter whether you're an Apple tech or not. After all, it's better for them if you buy a new Mac than fix the old one... p