Zapping the PRAM
Zapping the PRAM does not work on my iMac running SN. I used a wired keyboard but still no reaction?
iMac, Mac OS X (10.6.8)
And you were using CMD+Option or alt+p+r ?
18 replies
I am using option+command+p+r
What kind of reaction were you expecting when zapping the PRAM, please be specific.
Hi! No second chime. Just startup at the same speed as a normal atartup.
You have to continue holding down the keys until the second chime occurs. Please carefully follow the instructions in iMac SMC and PRAM reset
I am holding ALL keys down thru startup. I hold the keys down even after my desktop is shown. I have zapped PRAM many times on many MACs and this one isn't acting like ones in the past. I am zapping ( trying) the PRAM because of the first problem I posted that my external HD doesn't show on the desktop for about 2 minutes after the computer is up, negating a boot from the drive. I have done the SMC reset also. It is obvious the keyboard is working OK. I am familiar working with MACs since I have had a MAC since 1984. I am on a new iMAC, 21.5" made in 2011. The external HD was working fine as a backup HD. I reformated with GUID so it would boot from the drive and I installed SN. After the drive does come up, sys pref says it is a bootable sys. However, it won't boot because it take too long to come up so I have to retart holding down the option key to get back up. I am trying to get a bootable drive so I can install lion on my main HD keeping SN on the external HD. I hope this all helps. TY for your interest.
What is connected to the iMac when resettng the PRAM and SMC, ideally nothing should be except your keyboard and mouse. I would try zapping the PRAM without anything connected and see if it zaps correctly, if it does then that points the finger at one of the peripherals connected.
If the computer is less than 2 weeks old AND purchased from Apple then you can return it for another. At the very least it does have a warranty however my guess it's a peripheral issue.
Nothing is connected when I did both zap and SMC, except the keyboard. I am about to reinstall SN because I am running out of options. This computer is out of warrenty by 3 mos.
You did not buy Apple Care either?
You'r correct. I have never had a problem with an Apple procuct so thought Apple Care was not justified?? Oh well, one learn from his mistakes.
I think I now know what my problem is. When setting up my iMac, I set a firmware password, which I remember, but because of the password requiremant, you cannot reset the PRAM, OR, start up from an external disc, not even the install disc that came with my computer. I believe that this is also the root of my problem in not being able to boot form an external disc. So...my new question is..how do I now get rid of the firmware password so I can boot fron an external HD?? Remember, I cannot use the disc that came with my computer, nor can I put my computer into the target mode, or at least I don't think so. The only solution I can think of is to completely wipe the internal HD and start over.
AHA!
If you cannot turn it off/disable it, then...
Firmware password protection in Mac OS X ...
http://support.apple.com/kb/HT1352
It would block usage of all the startup keys, like C, N, T, D, CMD+s, CMD+Option+p+r, CMD +v, Option, and Shift, as well as booting from anything but the Hard Drive.
Force Removing Password Protection
1) Add or remove DIMMs to change the total amount of RAM in the computer.
2) Then, the PRAM must be reset 3 times. (Command + Option + P + R).
It appers that the only option I have is the one of removing RAM and since I have an iMAC, that is not a good option. The command in the "securemac" page of "option/command+O+F" won't work either. I think this whole mess is an Apple fiasco because there should be a warning in the firmware password set up on what happens when you set a password.
Well, I agree with you, but it's easy on most iMacs to change the RAM out, then do 3 PRAM Resets in a row, shutdown & replace the RAM. 🙂
Your'e right. It wasn't difficult and I have control again and my external drive is now accessable. Thank you for the advice
Zapping the PRAM