Yosemite architecture boards are notoriously temperamental and very sensitive to things such as poor ram, dusty connectors, PRAM battery issues, overclocking.... just about everything. I've owned 3 G3's... two Rev. 1 and one Rev. 3, and still have one of each, and a Yikes G4 which is essentially rev. 3 of the Yosemite logic board... It's near identical to the rev.2 except for the deletion of ADB and the inclusion of a G4 CPU boot enabler.... or more to the point a lack of a G4 boot disabler. Yep... they actually did that from what Ive read. Thanks Apple.
But yeh, I've played with em, overclocked em, modified them etc for over 10 years and all have given me headaches after altering configurations. My Yikes just tonight decided not to power on from the front button, which it and my Rev 2 G3 periodically do, meaning I have to drop the side and power it on with the button on the logic board. And then there are all the bootup issues... Nearly everytime ive changed a processor in one of them, or played with basic CPU clock settings, even sometimes just swapping out RAM for other RAM, I get a bong and no display startup, no boot sequence and a series of beeps, or power-on and then nothing. I worked out tho in a moment of pissed off desperation after one of my early attempts at a CPU overclock, that half the time its simply a matter of powering on with the cuda button held in until you hear a low-pitched, protracted "boooooooop" sound from the speaker (unless you shorted your onboard speaker once like I did so it no longer works), it should restart and bong, afterwhich you zap the PRAM a few times with Ctrl+Cmd+P+R and then allow it to boot... display will usually show and itll look for a drive and boot up, even tho it seemed 5 minutes earlier to be cactuar.
Thats actually how I procured my Rev. 1... me and a mate who were student admins were asked to build it up for my school 10 years ago as a hot video editing machine with G4 upgrade, big drives, max RAM etc. It was a temperamental, unstable lemon, partly due to the crap rev.1 IDE controller giving corruption issues, and partly as it turned out due to somebody using the 300mhz heatsink and not regreasing it causing it to overheat, and saw little use until it wouldnt boot one day and was put in a cupboard. My brother ended up with it sometime later and couldnt get it to work...so i convinced him to give it to me. After I pieced it back together, it wouldnt boot, but after some particularly frustrating mollycoddling and perserverance as above, and a few different combo's of RAM, even that one is now a functioning stable machine, with the stock 350mhz CPU out of my Yikes in it (as it still as the old Sonnet enabler flashed to the firmware) clocked to 400.
But yeh, I've played with em, overclocked em, modified them etc for over 10 years and all have given me headaches after altering configurations. My Yikes just tonight decided not to power on from the front button, which it and my Rev 2 G3 periodically do, meaning I have to drop the side and power it on with the button on the logic board. And then there are all the bootup issues... Nearly everytime ive changed a processor in one of them, or played with basic CPU clock settings, even sometimes just swapping out RAM for other RAM, I get a bong and no display startup, no boot sequence and a series of beeps, or power-on and then nothing. I worked out tho in a moment of pissed off desperation after one of my early attempts at a CPU overclock, that half the time its simply a matter of powering on with the cuda button held in until you hear a low-pitched, protracted "boooooooop" sound from the speaker (unless you shorted your onboard speaker once like I did so it no longer works), it should restart and bong, afterwhich you zap the PRAM a few times with Ctrl+Cmd+P+R and then allow it to boot... display will usually show and itll look for a drive and boot up, even tho it seemed 5 minutes earlier to be cactuar.
Thats actually how I procured my Rev. 1... me and a mate who were student admins were asked to build it up for my school 10 years ago as a hot video editing machine with G4 upgrade, big drives, max RAM etc. It was a temperamental, unstable lemon, partly due to the crap rev.1 IDE controller giving corruption issues, and partly as it turned out due to somebody using the 300mhz heatsink and not regreasing it causing it to overheat, and saw little use until it wouldnt boot one day and was put in a cupboard. My brother ended up with it sometime later and couldnt get it to work...so i convinced him to give it to me. After I pieced it back together, it wouldnt boot, but after some particularly frustrating mollycoddling and perserverance as above, and a few different combo's of RAM, even that one is now a functioning stable machine, with the stock 350mhz CPU out of my Yikes in it (as it still as the old Sonnet enabler flashed to the firmware) clocked to 400.