Apple Support Communities > Mac OS & System Software > Classic Mac OS (OS9, OS8 & System 7) > Discussions
This discussion is archived
3841 Views 4 Replies Latest reply: Sep 17, 2009 8:23 AM by Texas Mac Man
Currently Being ModeratedAug 29, 2009 10:40 PM (in response to No guru)Hi, No guru -
The monitor setting left in PRAM governs the initial display setting used by the monitor until the settings in the Display Preferences file (and/or the Monitors Preferences file) become available during the booting process. The settings in those files are usually transferred to PRAM during the shutdown process, so that they are available at the next startup.
Some things that may pertain or help -
1) The settings in PRAM may be mangled. This can happen for no known reason (just one of those things), or can be caused by a too weak or dead internal battery (those batteries have an expected life of only about 4 or 5 years under best-case circumstances). Suggestions for this -
• reset PRAM. This should return the monitor to an initial default setting of 800x600. Once the machine is fully booted, open the Monitors control panel and make sure the setting is the correct one. Then shut down (don't use Restart) and reboot a couple of times.
Article #HT1379 - How to Reset PRAM and NVRAM
• replace the internal battery if it is more than 4 years old, or if it is your practice to leave the machine unplugged regularly or for an extended period. You should be able to find a replacement at places like RadioShack for about US$17, cheaper on-line.
2) Either the Display Preferences or Monitors Preferences file (or both of them) may be damaged or corrupt. The solution for this possibility is to throw away the suspect prefs file, then restart. A new one with default settings will be created automatically. Once restarted (it will probably boot using 800x600 as the resolution), open the Monitors control panel and redo your settings. Then shut down (don't use Restart) and reboot.
3) Make sure that you have the separate Monitors control panel and Sound control panel, and not also a combined Monitors&Sound control panel.
If your G3 is not an iMac (hence has a separate monitor) and the monitor is a CRT type, it may have its own internal PRAM where it retains some settings, even wrong ones. The way to reset that PRAM on many CRT monitors which have separate video and power cables - power everything down, disconnect the video cable from the Mac. Then turn the monitor on, wait 15 to 20 seconds, then turn it off; wait about 10 seconds, then repeat the cycle, 3 or 4 times. Then reconnect the video cable and boot back up.G4/500; G4/733; various OS's, Mac OS 9.1.x, DSL, enet
Currently Being ModeratedAug 29, 2009 10:59 PM (in response to Don Archibald)Bless your heart for responding! I will try these tomorrow (getting too late tonight). With any luck, maybe one of your suggestions will work. I'll post my results, one way or another. Thank you!Power Mac G3 350 Mhz, Mac OS 9.2.x, 896 Mb Ram
Currently Being ModeratedSep 17, 2009 7:57 AM (in response to No guru)Resetting the PRAM worked. No problems since. The battery is also probably in need of replacing, as my clock will not keep correct time. However, resetting the PRAM is what fixed the problems I was having with my monitor. Thank you so much!!
Currently Being ModeratedSep 17, 2009 8:23 AM (in response to No guru)Great news!!!!!!!
Check this site for battery part numbers and sources. Mac PRAM, NVRAM, CUDA/PMU & Battery Tutorial
Cheers, Tom G4 1.25MHz MDD, G3 400 FW Pismo,, Mac OS X (10.5.6), OS 10.4.11/9.2.2, Canon LiDE30 Scanner, Canon i960 Printer, Belkin UPS