Black screen when trying to boot beige PowerPC G3

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Level 1

19 points

Black screen when trying to boot beige PowerPC G3

I have a 1997 vintage beige PowerPC tower, with OS 9 (not sure which version, I think the last one it would run - 9.2.2?). It's been sitting in the corner, powered off but plugged in for years (on a surge protected UPS along with newer computer). It's probably been 2-3 years since the last succesful power up to retrieve something from it. I'm wanting to see about getting some data off of an old program on it, but can't get any display from it, just a black screen.

Here's what I know about the hardware:

Label says PowerPC G3 233 MHz 512K Cache, 32MB/4G HD/24x CD/56K Modem, 2/17/98

The memory may have been upgraded long ago, there are 3 SIMMS in it.

I'm using built in video port, with an adapter to go from Apple Display Connector to VGA, an adapter that worked fine all the years I used the computer.

When I power on, her is what happens:

I get the normal "chime"

The monitor it is connected to wakes up from sleep mode

The display goes completely black- (no happy Mac, sad Mac, or any Mac or gray screen)

The monitor never goes back into sleep mode until I power down the Mac (at least for the 10-15 minutes I have let it sit at one time). This makes me think the video port is sending something to the monitor.

Here is what I have tried so far:
Tried 2 different monitors and cables, both of which checked out on other computers (relatively modern flat screen LCDs)
Replaced the on-board battery
Zapped the P-RAM
Re-set the NVRAM by booting with command-option-O-F and blindly typing
- reset-nvram (press enter/return)
- reset-all (press enter/return) - at which point it re-booted so assume it took the commands
Booted with space bar pressed to see if extension manager would come up
Re-seated the memory SIMMs (I seem to recall when a memory SIMM went bad once years ago, I got a "breaking glass" sound on boot so I'm thinking the memory is OK?)

The only things I can think of to try are changing out the ADC to VGA adapter, and putting in a PCI video card. Wikipedia lists a couple that were popular with this vintage Mac: ATI Radeon 7000 & 9200. Will these work without having to install any drivers? It looks like http://www.amazon.com/ATI-Technologies-Radeon-7000-Graphics/dp/B0000630TB can be had pretty cheap, I just don't know about drivers.

I have not tried booting from CD-ROM, mostly because I haven't been able to locate them. I might look harder if it's reasonable to expect a different result but this seems like a more fundamental issue. If there are any vintage Mac people with ideas, it would be greatly appreciated!

PowerPC G3-OTHER, Mac OS 9.2.x, Beige 1998 Tower 233 MHz 512 K Cach

Posted on May 8, 2016 4:47 PM

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Answer 1

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Jeff

Level 6

12,058 points

May 9, 2016 4:49 AM in response to Ray Earley

The Amazon link that you've posted is for the PC version of ATI's Radeon 7000. You need the Mac version or a PC version that has had its EEPROM chip reprogrammed with Mac code. Fifteen years ago, I bought eight of the retail-boxed, PC version Radeon 7000s and flashed the ROM, for use in my beige G3s. It required OS 9.2.2 to support the latest drivers that enabled 2D acceleration. The Radeon 9200 Mac Edition was the final PCI graphics card that they marketed for Macs and would cost more and be more graphics card than you need, just to retrieve files from the G3. You may be able to find an inexpensive, Mac-compatible Radeon 7000 on ebay. For that matter, the older (Mac-compatible) ATI Rage 128 PCI graphics card from a B&W G3 (shown here) would be well-suited for your needs. When you zapped the PRAM, how many times did you let it go through the restart cycle, while still holding down the "Command + Option + P + R" keys? I usually gave it three. You might try removing the audio "personality" card and clean off any oxidization on the gold-plated pins with a soft, white eraser, and reinstall it. The same would be the case for the memory DIMMs and ROM card, which can also become oxidized over time. If the Mac DB-15 to VGA adapter that you have has a set of adjustable DIP switches, the (resolution) settings may be different for the newer LCD displays that you tried out, especially if they have a widescreen aspect ratio. You might also want to check out the "Startup Failures Checklist" on this page from Accelerate Your Mac's "G3 Zone." There was a problem with the first batch of voltage regulators used in the beige G3s, but I think they had switched to the Raytheon VRM by February 1998. If "Raytheon" is printed on your VRM, you can likely rule that out as the problem.

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Answer 2

Ray Earley Author

Level 1

19 points

May 9, 2016 5:00 AM in response to Jeff

Thanks Jeff. That's definitely the kind of thing I was worried about on the video card. I'll give the contact cleaning a shot. I zapped the PRAM multiple times (after changing battery, after changing resolution dip switches on the video adapter), and each time held it down for 3 or 4 chimes. The monitors seem pretty good at adjusting to the resolution coming in, but I've got the dip switches set for 1024x768, the same resolution as the PC I tested it on, so I don't think that's an issue. Good info on the voltage regulator too, I'll be sure to check that. It may be a few days before I can break it open again and try/check your suggestions, but I'll post back when I learn something.

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