How to ged rid of the BANG and flashing screen?

aart, "BANG" sounds and "flashing screens" are abnormal.

How long have you had this Mac and how long has it been flashing and banging?

Run "Apple Hardware Test"?

If CD's came with your computer it is on a CD labeled "Hardware Test" To test with CD, insert the CD and restart holding the "c" key until you see the spinning gear.

If DVD insert DVD then:
1. Turn on or restart the computer.
2. Immediately press and hold the Option key. After a few seconds, the Startup Manger screen appearsThe Startup Manager scans for available volumes.
3. Optional: Clicking the circular arrow rescans for other volumes, including NetBoot Server volumes. You can eject any disc in the drive or open an empty tray-loading drive by holding down the Command (Apple) and Period (.) keys. The Command-Period key combination will also close the drive. After inserting a CD capable of starting up your computer, you could rescan for volumes.
4. Click the startup volume you want to use. "Hardware Test"

If hardware test does not mount or does not run bring the computer to Authorized Apple Repair.


-mj
macjack@gmail.com

When you say a bang, it sounds like it could be a hard drive problem, which is why I asked you to check hardware. The test is not definitive.

For the flashing screen, can you operate System Prefs? If so create a new account, name it "test" and see how your desktop works in that User acct? (That will tell if your problem is systemwide or limited to your User acct.) This account is just for test, do nothing further with it.

Open System Preferences >> Accounts >> "+" make it an admin account.

If not, Try booting in "safe mode" if you can. Restart and hold the "shift" key.

Let us know and we'll troubleshoot this further.


-mj
macjack@gmail.com

Try safe mode, like macjack said.

Since it's not account specific, you may be able to repair this with the 10.4.6 Stand Alone Combo Updater.

This is a fuller install, as opposed to an incremental "delta" update so it should overwrite any files that are damaged or missing. It does not matter if you have applied it before. It has worked well for many.

Remember to Verify Disk before update and repair permissions before and after update from /applications/utilities/disk utility.

You might also try resetting pram/nvram:

1. Restart your computer
2. While it is booting up, press and hold these keys command option+pr
3. Your computer will chime and restart again, this is supposed to happen, do not let go of the keys.
4. Let your computer chime (or BANG) twice, and then let go of the keys.



-mj
macjack@gmail.com

Hi, aart.

1. You wrote:

"The 'bang' is a soundfile (WAV ?) like the sound when Windows start. I mean to heave read somewhere that there is a way to increase the volume."

Having a little trouble understanding you here, but are you talking about the startup chime — more like a "Bong" sound — a chord that plays when you startup your Mac? If it's too loud, simply decrease the volume on your Mac or any connected external speakers before shutting down.

You can find utilities to completely disable the startup chime or startup sound as it's sometimes called, by searching MacUpdate or Version Tracker. I don't recommend those, however, since the startup chime will change to sounds like broken glass or musical beeps to indicate problems with your hardware when you startup. Disabling the startup chime would render those mute as well.

2. re: Flashing screen. Check System Preferences > Universal Access > Hearing. Deselect "Flash the screen when an alert sound occurs" if selected.

Good luck!

😉 Dr. Smoke
Author: Troubleshooting Mac® OS X