When I try to reset my PRAM MBP, Late 2013, Mojave I do NOT get succeeding chimes as I have in the past for older computers and/or OSX. I followed Apple support instructions as I have in the past. How can I tell if I have successfully reset my PRAM?
MacBook Pro 13", macOS 10.13
Pay attention to the screen and watch for the backlight to light up and go dark. This is harder to see on the Retina laptops, but it is possible if you look carefully (it takes practice to see).
Even if the sound is muted the PRAM reset should reset the audio settings to system defaults which should be heard if you continue holding the PRAM reset keys. I've seen a few older systems that would not reset the PRAM more than once (one chime). I assume this is due to a hardware issue of some sort (probably the Logic Board). As soon as the system begins to boot any macOS audio settings may trigger the audio to be muted again. Newer Macs with a T2 chip only allow the PRAM to be reset one time.
You can also reset NVRAM through Terminal
nvram -c
... then restart your Mac.
"...nvram -c ..."
Silly question maybe, but with that command available why are we asked to faff around with multiple key rebooting as default method?
Al Mayberry wrote:
When I try to reset my PRAM MBP, Late 2013, Mojave I do NOT get succeeding chimes as I have in the past for older computers and/or OSX. I followed Apple support instructions as I have in the past. How can I tell if I have successfully reset my PRAM?
You do not say what exact Mac /model /year /size /retina /touchbar is this
or
what exact macOS you are currently running?
If this is a T2 chip enabled Mac pay strict attention to the exact keys in this "new" protocol:
resetting NVRAM/PRAM http://support.apple.com/kb/ht1379
if no success then Try resetting the SMC https://support.apple.com/en-us/HT201295
as well. Try again —no harm in repeating this sequence 2-3 times.
In addition to John's point, I have an older MBP that should chime, but if I turned off sound before shutting down it remembers and does not chime on booting.
Sounds good. Mine only ever chimes once. Don't confuse the DVD whirring noise with the chime if it had one. (Yes mine has one!!)
They may chime several times with OS updates or installs.
Leroy--hmmm it says "MBP, Late 2013, Mojave" I can add 13" and it is not T2 and is retina. I did all that = reset SMC, tried DPRAM over & over and was at both of those links for instructions. I've done all this now & then in the past (had Macs since '88) and it would always play start-up chime several times. I was wondering if Mojave and newer Macs still did this repeated chime thing (that mine isn't doing)--AND is there a way to tell if PRAM has been set?? Thanks, A
For one thing the PRAM reset has been around since the PPC days where the "nvram" command was not available. Plus using the multiple keys is much easier than instructing people to boot in a special manner and enter cryptic commands. Plus it is easy to mistype the command which could cause other problems.
...And Peter--I did not have sound turned off and it did do its regular start-up chime once = the problem seems that it did not REPEAT the chime as it seems it should--no?? Thanks, A
Beats me. I think Apple described it as an alternative in a Support document but I can't find it now.
For completeness, Macs from 2016 onwards lack the chime by default, but it can be enabled:
sudo nvram StartupMute=%00
To re-enable:
sudo nvram StartupMute=%01
A reboot is required.
PRAM Chime??