>By removing the iMacs video plug and thus cutting off the video signals, it >also removes the H&V syncs. Without these syncs the monitor section goes >into power saving. Power saving cuts off the B+ voltage to the flyback, so >if faulty it will not operate and trip the power supply. Note that other >components could fail that would not be effected by pulling the video >connector, and could shut down or stop the iMac from starting.
Ok, that finally gives me the definitive answer I was looking for. That my problem has nothing to do with the Analog board, since it occurs regardless of if the internal video is connected or not. >The most common Analog board failure item is the flyback transformer. To >find any other problems you would need component level fault finding >experience, which you don't have or you wouldn't be asking these questions. Correct. I have the skills to swap components, but I'm not very good at testing anything in circuit to find bad components (for that most of my skills stop at the usual tech level of board swapping). That is exactly why I was asking. If I know what part may be bad, then I can check it, but to search down bad parts when I don't know exactly what I'm looking for, that's still a little above me. I did go as far as metering the power supply output and everything there looks normal. So I'm leaning towards a failure on the logic board. I'm planning to swap in a rewired ATX power supply later just to verify, but I'm not expecting it to solve anything. Its looking like this iMac will end up being shelved as a parts machine for later. Thanks for the help. -chris <http://www.mythtech.net> -- The iMac List is sponsored by <http://lowendmac.com/> and... Small Dog Electronics http://www.smalldog.com | Refurbished Drives | - Epson Stylus Color 580 Printers - new at $69 | & CDRWs on Sale! | Support Low End Mac <http://lowendmac.com/lists/support.html> iMac List info: <http://lowendmac.com/imac/list.shtml> --> AOL users, remove "mailto:"; Send list messages to: <mailto:[EMAIL PROTECTED]> To unsubscribe, email: <mailto:[EMAIL PROTECTED]> For digest mode, email: <mailto:[EMAIL PROTECTED]> Subscription questions: <mailto:[EMAIL PROTECTED]> Archive: <http://www.mail-archive.com/imac-list%40mail.maclaunch.com/> --------------------------------------------------------------- >The Think Different Store http://www.ThinkDifferentStore.com ---------------------------------------------------------------
