How do I fix loud alarm sound and no video audio on iMac after power outage?

Power went off last week. When iMac restarted there was a loud alarm sound. The alarm went off when I did a restart . But ever since, videos have no sound!! This morning,I tried to reset RVRAM --- this caused the alarm all over again !!!!


using Sequoia 15.7.7


TY forr ur help!



[Re-Titled by Moderator]

Original Title: iMac loud alarm sound!

iMac 27″, macOS 15.7

Posted on Aug 11, 2026 11:46 AM

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2 replies

Aug 11, 2026 12:28 PM in response to puggybomac

The NVRAM (PRAM) reset with continue chiming until you let up on the keys.

see > Reset NVRAM on your Mac - Apple Support


If the iMac is still chiming after startup or not starting up at all.

Try resetting the SMC followed by another MVRAM reset.

see > Reset the SMC of your Mac - Apple Support


Then after the SMC and NVRAM resets.


If the iMac is not turning on at all or just sitting there chiming...?

see > If your Mac doesn't turn on - Apple Support


Or if the iMac is turning on but not completely starting up...?

see > If your Mac doesn't start up all the way - Apple Support

How do I fix loud alarm sound and no video audio on iMac after power outage?

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