I recently got ahold of a Revision A Bondi Blue iMac and was ecstatic to discover that it was still operational. That is until I got the system software installed again and started using it. Every so often I'd hear a fairly loud "crack" usually accompanied by the image on the screen jumping or distorting and, occasionally, it would even shut off and come back on a second later and make a "degaussing" sound ("bummvvvv"). I figured that this would be a problem I'd need to address at some point soon but in less than an hour those occasional "cracks" turned into a constant loud buzzing (as if something was arcing, but without any kind of smell or smoke that I would associate with this). I figured it was probably a capacitor issue but, after disassembling the machine and removing both the power supply and analog boards, there is no obvious sign of bad capacitors (none sticking out at odd angles, no visible leakage, and no bulging). I know that's not conclusive at all, but, given how many capacitors there are in this thing I'd rather not have to replace all of them if it's not necessary (which it probably shouldn't be). After doing some research to see if there was any capacitors that are known to go bad I discovered that, actually, in these it's more often the flyback transformer that went bad. The symptoms don't line up with what's reported for a flyback transformer (it turns on, runs fine, the screen never died completely), but I think it's likely that what I have is just the very early symptoms that many people wouldn't have caught in time.
As I understand it flyback transformers aren't identical, even within the same product line, therefore I'd need to get the exact same one. The part number on my FBT is 6174z-1003g which seems to be very hard to find, however, there are a couple of 6174Z-2001G and a 6174Z-1003D FBT on ebay, and I wonder if anyone knows if one of these are close enough to work.
As I understand it flyback transformers aren't identical, even within the same product line, therefore I'd need to get the exact same one. The part number on my FBT is 6174z-1003g which seems to be very hard to find, however, there are a couple of 6174Z-2001G and a 6174Z-1003D FBT on ebay, and I wonder if anyone knows if one of these are close enough to work.