Since today our iMac has suddenly stopped booting.. It's been a while since we used the keyboard on it due the dog eating through the USB cord.. (been operating it using VNC) Today I fixed the USB cable successfully, keyboard worked fine.., but since the mouse was ALSO eaten (damn dog :P ), I decided to plug in an optical USB mouse to the keyboard.., then things went bad... It jumped out of powersave mode with a garbled screen, no sweat, let's reboot it.. And that was the last we saw of the iMac.. When we turn it on now, it just plays the chimes theme, and falls silent, power LED stays orange, screen doesn't turn on.. We've reset the NVRAM using the command-option-p-r (that works, so the USB port is still in working order), to no avail.. We replaced the RAM with another stick.., no avail.. I tried hitting the CUDA switch.., still nutn.. I even tried command-option-o-f and then typing blindly: reset-nvram reset-all mac-boot Nothing happens.. Also tried disconnecting everything non-vital, disconnected all USB devices, disconnected the HD and CD-Rom, even the videoconnector.., but it still doesn't do anything more then playing the chimes thing when we start it up.. Unfortunately I don't have a battery tester here to test the onboard battery, should an iMac boot without the battery attached or when it's empty ? Anyone has any clue what could be broken ? (my first guess would be that I fried the main board somehow)

Wunk, If you install a fresh new 3.6 volt Lithium Battery and it still fails to start-up, then your last conclusion would appear to be correct. it sounds like the logic board has fried - often happens when iMac is not connected via a surge protection unit with unbuilt circuit breakers - electrical spike shoots up the chord and bang - no wakey. Either that or you were not "grounded" (earthed) well enough before and during disessembly - touch metal and do not move around too much. Two other possibilities: 1. If you've disassembled the iMac several times - removed the HD and so forth - it's possible that the gold pins on the communications cable to either the HD or the CD-ROM have become accidently "bent". This will definately cause an iMac to go dead - so possible replacement of the IDE cable. (Touching the gold conduits on the RAM sticks will also kill it). 2. If your iMac is connected via an extension chord to the wall socket, try removing the extension chord - shifting the iMac closer - and plugging it straight into the wall. 3. Tie a piece of string round the dog's balls and tie the other end round its ankles - then... hang a chop over its head in order to get it spring up on its hinds to reach the meat. When you boot up, does the optical mouse's red light come on, or is it "off" too? Try the above two methods - also try unplugging the entire keyboard and plugging in a regular trackball mouse and see if it starts up. Also attempt all these methods whilst booting off the Mac OS 8.x or Mac OS 9.x Install CD, by holding the "C" key down on restart the moment the screen goes black. tell us what happens cheers clockwork