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� · Apr 7, 2002, 06:33 AM

Gee, maybe someone can help me.

I accidently put my screen resolution to 1600x1200 at 120 Hz. Now the screen is black.
Rebooting starts up in 640x480 but when the extensions kick in it goes back to a black screen.
I have a big fat manual about troubleshooting macs, and am advised to reboot and zap PRAM.
However, I never in my entire life, on whatever macintosh, managed to use a keycombination to zap pram. Maybe that is because apple nowhere points out where the command key is. They just assume you know that. So clever!

So, how do I get back to 1024x768 without wiping my harddisk?
And could somebody please tell once and for all, where the command key is?

I am not in a rush, the sun is shining

Too Much Coffee Woman · Apr 7, 2002, 11:14 AM

command - option - P - R

or trash monitor preferences

� · Apr 7, 2002, 11:47 AM

I have tried that, trashing the prefs. didn't work.
I still dont know how the command key looks like.

gto47 · Apr 7, 2002, 12:24 PM

The command key is the apple key located between the space bar and the option key.

bil207 · Apr 7, 2002, 12:30 PM

If you are still having problems try trashing the Display preferences.

� · Apr 8, 2002, 06:20 AM

i.t.r.i.e.d.t.o.t.r.a.s.h.d.i.s.p.l.a.y.p.r.e.f.e. r.e.n.c.e.s

siegzdad · Apr 8, 2002, 06:44 AM

To "zap the PRAM" you need to hold down the command, option, P and R keys while starting the computer (before the happy mac icon appears).

Keep holding the keys and you should hear the startup chime a second time. The PRAM is now reset.

The command key is the Apple key (or the puppy paw looking one). If you use a windows keyboard, it is the windows key, unless you use software to map it to its normal location of right next to the spacebar, in which case (as on my MS keyboard) it is the Alt key.

Tom N · Apr 8, 2002, 09:04 AM

I have had the same problem as originally mentioned. Zapping the pram and tossing prefference will not reset the monitors resolution settings. Even tried booting from an Apple install CD, no luck. Don't ask me why, you think it would, but it does not. I have not tried reseting the motherboard, so if you wish you can try that.

I have only been able to reset the monitor resolution by connecting the computer to a hi rez monitor and then reseting the monitor resolution using the control panel.

If you are using OS X, you could probably boot to the console (or single user mode). this gives you access to a command line. If you know what the name of the monitor application and its command parameters, you could issue a command to set the resolution to another value. However, I don't know what the command would be.

If anyone does, it wold be a good to know for troubleshooting.

Tom N.

� · Apr 8, 2002, 10:37 AM

Thanks Tom (and other helpful posters). I got the previous answers (zapping PRAM and trashing monitor prefs) straight from expensive apple-troubleshootingbooks. And appearantly, it doesn not work on all macs.
Unfortunately, all the apples I previously owned are not that regular.

Anyway, I also managed to set my monitor to a lower Resolution. again by using TECHTOOL and not by using the MACOS.

IN SHORT :
As I set the resolution to an impossible 1600x1200 @ 120hz, my monitor became black. (I leave in the middle why macos9.2 offers this impossible resolution as "recommended" and i was able to make this mistake)
I rebooted and thought i would be able to reset the videosettings. I was not. I rebooted with the 9.2 installation cd and threw away my monitor files. Still the monitor went to 1600x1200 and remained black.
I tried for the maniest time in my 3 year long maclife to zap PRAM but that did not work as well. I tried TECHTOOL for this too, to no effect.

Then I used TECHTOOL 302 , and booted from that diagnostic cd. In TECHTOOL you are able to reset PRAM and check your motherboard and amongst others, put your screen resolution to 640x400.
Now, the funny thing was that after a restart, my resolution was not 640x400, but in the middle : 1280x960. From this resolution I could get back to 1024x768@85 Hz.

Hurray for MACOS.

residentEvil · Apr 8, 2002, 03:52 PM

when i've done something wrong with my video settings, and i can't get them back to what i want (be it a pc or a mac) with it's control panel, restarts, etc: i simply unplug the monitor from the video card and reboot. let some time pass, so you know it has fully booted and waiting for a login or at the finder. with the monitor POWERED on, plug the video cable into your machine. either be it the OS talking to the video card driver's or what have you, the monitor will default to a 640x480 image. since the OS didn't have a chance to sync at startup, it will be forced to use what the monitor is saying its set at.( a monitor out of the box, powered on and not plugged into a video card/etc will have as a default setting 640x480). from the control panel, i then set it to what i want. followed by a reboot. and i'm back in business. as i don't have every machine or video card, i can't tell you this will work with what you have. on older pcs with trident video cards, this worked every time. on several occasions with a video card in my 6400 and 8500 i did this and it worked.

(i have not tried this with W2K or OSX. i will say it will NOT work on W2K because of all the damn plug and play crap it does, unless you have turned that off.)

� · Apr 8, 2002, 06:08 PM

thanks, maybe it works with my ati 128 rage pro as well. I have 2 21" screens plugged into it

superlarry · Apr 8, 2002, 06:09 PM

Originally posted by residentEvil:
<STRONG>when i've done something wrong with my video settings, and i can't get them back to what i want (be it a pc or a mac) with it's control panel, restarts, etc: i simply unplug the monitor from the video card and reboot. let some time pass, so you know it has fully booted and waiting for a login or at the finder.</STRONG>

i had the same problem as �, and residentEvil's comment was offered to me, too, and it was effective until the next time i booted with the monitor plugged into the computer. what i ended up doing was blindly searching for the "displays" menu icon (it looks like a flatscreen display). what i suggest from this experience:
in the "Displays" pane of the OSX system preferences, make sure "Show displays in menu bar" is checked. it will show up somewhere on the top right of your screen in the menu bar. now, command-click it and drag it to be the right-most item.
it should still be there when you reboot (i assume.. i sure hope so). that way it's at easy access for blind clicking and dragging - move the mouse to the upper right until it's obviously going to be at the extreme upper right. move slightly down and to the left, then click and drag down the little menu to presumably one of the first choices, which should be an 800x600 or so that your monitor *can* handle.
it's all 'bout trial and error, i suppose.

[email protected] · Apr 11, 2002, 09:03 AM

Originally posted by �:
(...) Then I used TECHTOOL 302 , and booted from that diagnostic cd. In TECHTOOL you are able to reset PRAM and check your motherboard and amongst others, put your screen resolution to 640x400.
(...)[/QB]

I haven't tested this, but I think that it would have been possible (on B/W G3s and G4s) to push the reset button on the motherboard to fix this.
Just in case zapping the PRAM the ordinary way doesn't work. (The reset button is a small coloured plastic knob in a small square metal frame/box. It's placing differs.)

Bankmann