[HazMacFan]

Got a Rev B. iMac G5 20". It froze today while in Safari. I powered it off after the fan just kicked in full blast.

I unplugged everything from it except the keyboard and mouse. Powered it on and same results, gets power, little sound as the power indicator is on, then blast-off, fan full speed.

I reset SMU, I reset PRAM, same result.

I opened it up and pulled the crucial dimm, same result. I pulled the Apple (Samsung) dimm, same result.

Any suggestions what could be wrong?

[volcano]

Can you boot it up in safe mode?

Hold down the shift key right after you hear the startup tone, and let go after you see the gray screen with the Apple logo. If you have to enter login information, you'll see 'Safe Mode' on the main login screen.

[HazMacFan]

Originally Posted by volcano

Can you boot it up in safe mode?

Hold down the shift key right after you hear the startup tone, and let go after you see the gray screen with the Apple logo. If you have to enter login information, you'll see 'Safe Mode' on the main login screen.

No dice. The glow (power light) stays on, the fan full blast but the screen stay black.

No light when I push the Caps-Lock, no light under the mouse when I move it.

I even tried without keyboard and mouse. With either same result.

[matrk]

has anyone else got a tip on what could fix this imac g5 (rev.b)??
i have same problem as original poster - the imac froze with dark screen, after forced shutdown it doesn't boot back up. No startup chime, no display, only the front white light goes on.
can't insert startup DVD either.
this imac g5 rev.b isn't on the apple logic board failure list - but could it be afflicted with the same problem??
is there no other remedy other than sending it into an apple shop?
i'm half the world away from where i bought this (australia), alas, and don't speak the local lingo here in berlin, germany...

[Vahtang@apollo.lv]

Have same problem rev.B Imac20, don't know what to do, it's started few days ago :S

[larrinski]

My first(OK my second after doing what you have tried) thing is to get a hold of Apple. Online support will create a case # for you while you try to get a fix. Telephone support may be good as I find typing the problem is not as easy as talking to someone about it...

[matrk]

... to a local apple tech shop here in berlin.
i couldn't work out what else to do, despite my nearly 2 decades of mac d-i-y usage
like many of us of course, my biggest concern is about losing all/any of the data in the hdd, followed by total failure to revive this imac (g5 20-in 2ghz/rev.b/1.5gb ram/250gb hdd) and the potentially great expense involved
mind you, going back to using my old pb 12-in (rev.A) hasn't been too bad and i'd forgotten how wonderful this keyboard is - surely the best laptop keyboard bar none? shame it doesn't work with FCX or photoshop files quite as fast as my imac though.
here's hoping it's just a power supply problem, rather than logic board (or worse) failure...

[Vahtang@apollo.lv]

now my mac don't booting, but I maked backup copies of all files what I use. Tomorow going to service.