At 8:40 AM +0800 2/22/2003, Charlie Reyes wrote: > >> It sounds as if a power-associated 'event' may have >>> taken out your power >>> supply, and damaged electronics associated with the >>> internal SCSI bus as >>> well (killing the bus). >>> ---Alex >> > >Power supplies have protection circuitry to limit stray electrical surges >from causing haboc to the motherboard and peripherals. Its MOSFET absorbs the "shock" and blows up before it hurts the rest.
It's MOVs (Metal Oxide Varisistor IIRC) not MOSFETs that absorb surges. MOSFETs are the likely switching device. A little known fact about MOVs is that they wear out with usage. The more surges and the more powerful the surge, the sooner it wears out. When they were "gently" they typically fail open, thus no longer providing any protection. When they wear out with a large surge they tend to short out. And you would be surprised just how much smoke a little sucker like that can make (especially when you hit it with 220 VAC @ something in excess of 70A. I can't say if it was a problem in this case but it can happen. -- Clark Martin Redwood City, CA, USA Macintosh / Internet Consulting "I'm a designated driver on the Information Super Highway" -- PCI-PowerMacs is sponsored by <http://lowendmac.com/> and... Small Dog Electronics http://www.smalldog.com | Refurbished Drives | -- Sonnet & PowerLogix Upgrades - start at $169 | & CDRWs on Sale! | Support Low End Mac <http://lowendmac.com/lists/support.html> PCI-PowerMacs list info: <http://lowendmac.com/lists/pci-powermacs.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/pci-powermacs%40mail.maclaunch.com/> Using a Mac? Free email & more at Applelinks! http://www.applelinks.com
