233 MHz G3 Compatibility with Sony SDM-X52 15" LCD Monitor

Question

Trying to interface the subject items, the monitor recognizes the Mac's video output on its input #2, but shows the error "Scan Out of Range," and "Frequency 43.3 Khz/85 Hz." According to the Sony manual this means the horizontal scan frequency is 43.3 KHz, which is within the monitor's range, but the vertical frequency needs to be 56 - 75 Hz. The graphics card in the G3 is the original OEM ATI Rage II+, which Apple states "supports refresh rates up to 85 Hz." However, I haven't the slightest idea how to reduce that rate to between 56-75 Hz.
There is an adapter on the G3's monitor output which allegedly converts to a VGA/SVGA signal, and it does mate with a cable that is compatible with the Sony monitor. This adapter contains slide switches and a rotary dial, and a label on the bottom which identifies the characteristics for its various settings. The G3 was previously interfaced with a CRT monitor, and worked fine. The current settings on the adapter are for 640x480/800x600 resolution with vertical and horizontal sync signals active (these can be turned off but have not tried that).
The adapter has no manufacturer name or logo, only an icon of the Liberty Bell molded into its case.
Would anything I do to this adapter's settings change the vertical scan frequency?
(BTW, the monitor works perfectly on its DVI-D input #1 with my G5.)

Answer 1

Hi, Bill -
The reason I asked if you had another monitor, is that the initial settings (the ones used at the beginning of startup) for the monitor are stored in the Mac's PRAM. After the OS has loaded sufficiently for additional or other settings (if they are different than those in PRAM - not common, but possible, especially when switching from one OS to another) in the appropriate prefs file(s) to be read, those take over.
If you had a different monitor to use, you could use it to get the machine running, then use the Monitors control panel to reset the resolution and frequency to a combo acceptable to the monitor. Then shut down, swap monitors, and give it a try. When the machine is shut down, the applicable settings in the prefs files are transferred to and stored in PRAM, making them the initial governing settings at the next boot.
You might try a reset of PRAM (zapping the PRAM, in old lingo). Doing this should reset the settings in PRAM to the default ones, probably 480x600 @ 60Hz for your model. Later model G3s and G4s default to 600x800 @ 60Hz.
Article #HT1379 - How to Reset PRAM and NVRAM
If that works initially, then immediately press the Shift key and keep it held down until the desktop has loaded. This will prevent the Monitors control panel (along with other control panels and non-critical extensions) from becoming active - and with a bit of luck will prevent the prefs file from being read.
If that works, then go into the Preferences folder in System Folder and trash the Display Preferences and Monitors Preferences files. Empty the Trash. Then try a normal restart.