Hi Robert, Are you using a 7200 rpm or faster SCSI drive or the standard 80/160MB drive at 3800rpm ? The faster ( high rpm ) SCSI drives draw way too much power to install them in the Colour Classic. The PSU is just not up for this.
Have a look at the hard drive power requirements on both the 5v and 12v lines. In the spec sheets ( Google them ), you can often find the spin-up current the drive needs, which is way more than the number on the drive: these are just for idle/working mode. Sometimes these more recent/faster SCSI drives work for a while in Compact Macs like to colour classic but in the end the regulators and capacitors in the PSU get overloaded and brake down. Also when a drive gets older, you often get "stiction" of the heads, which even asks more power to get the heads out of the parking position: then you see the hard drive typically spin up and down a few times on power-on before it completely shuts down. Nico -----Oorspronkelijk bericht----- Van: [email protected] [mailto:[EMAIL PROTECTED] Namens Robert McAllister Verzonden: zondag 19 oktober 2008 20:31 Aan: Vintage Macs Onderwerp: Mystic Color Classic Low Voltage Mystic Color Classic with LC 575 logic VGA modification to the analog board Apple IIe card installed A while back the hard drive in my CC started having problems. It won't boot or when it does will stop working. I tried two other known working hard drives and neither will work properly. I measured the voltage of the power connector and +12v is only 11.5v and +5v is only 4.5v. Is this enough to cause problems with the hard drive? Would a bad capacitor cause both +5 and +12 to be too low? If so, any idea which one? -RPM --~--~---------~--~----~------------~-------~--~----~ You received this message because you are subscribed to the Vintage Macs group. The list FAQ is at http://lowendmac.com/lists/vintagemacs.shtml and our netiquette guide is at http://www.lowendmac.com/lists/netiquette.shtml To post to this group, send email to [email protected] To unsubscribe from this group, send email to [EMAIL PROTECTED] For more options, visit this group at http://groups.google.com/group/vintage-macs?hl=en Low End Mac RSS feed at feed://lowendmac.com/feed.xml -~----------~----~----~----~------~----~------~--~---
