In a message dated 5/22/02 2:10:15 AM, [EMAIL PROTECTED] writes:
<< My 9600/233 is missing one of the two screws that hold the rear hard drive carrier in place above the power supply. What kind of screw would I need to replace it? >> Although many Apple Certified techs will tell you that a PCI machine is a PCI machine is a PCI machine, and therefore the 6-32 Unified National Coarse (UNC) screw, as used on PCs, is correct, this is simply no so. The correct screw is an M3.5-0.6, which is an obsolete size, usually only available from specialty screw manufacturers. Oh, and Apple ... although Apple techs will probably tell you to use 6-32 UNC. The 8600/9600/G3 MT case makes extensive use of M3.5-0.6 screws. In fact, these cases use M3.5-0.6 screws wherever a 6-32 UNC screw might otherwise be used. Historically, Apple adopted M3.5-0.6 screws with the Mac 128, while M3.5-0.6 screws were still being classified as a common fastener. But, by the time the NuBus Macs had appeared, the M3.5-0.6 screw was already obsolete. However, as there was no metric screw with the required shear strength, Apple continued to use this screw on all its models, just to keep them all metric. You can easily make the mistake, as I did, of using ... on an Apple Certified tech's recommendation ... a common 6-32 UNC screw, but then your case is screwed (pun intended). The easiest way to get M3.5-0.6 screws of the required length is to take a 6-32 UNC screw of the closest corresponding length and rethread it using an M3-0.6 die, which is available from many industrial machinery suppliers [ * ] . A 1/4" long 6-32 UNC screw is a perfect candidate for making replacements for most drive bracket/tray attachment screws for 8600/9600/G3 MTs. A 5/8" long 6-32 UNC screw is a perfect candidate for making replacements for motherboard attachment screws for most Macs which utilize these screws (Mac II and later, but most particularly all PCI Macs). [ * ] If you farkle-up your case by mistakenly using a 6-32 UNC screw where you shouldn't, you might be able to restore the threads using an M3.5-0.6 tap, but these taps are very difficult to find, whereas M3.5-0.6 dies are pretty easy to find. Peter. -- 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
