Author Topic: No video shortly after boot on Mac Mini G4  (Read 482 times)

Offline rbdr

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No video shortly after boot on Mac Mini G4
« on: January 08, 2024, 06:33:57 AM »
Hi Everyone,

New to the forum. I just got my hands on a Mac Mini G4 and wanted to play around with it. I'm connecting it to a Philips 275E monitor via an HDMI adapter and am having some issues with video: Whenever I boot an installer disc, the video doesn't come back.

The computer doesn't have an OS: I burned the Mac OS 9 lives CD from macintoshgarden, and I have an original 10.4 install disc that came with the mac. Whenever I boot both I get the same kind of behavior:

- With the Mac OS X disk I see the grey apple logo loading, I was able to see a small flash of the next screen after load but then the video goes away.
- With the Mac OS 9 I see the grey screen but it then stops outputting video.

I tried resetting pram on boot, resetting nvram on open firmware and different monitors I have at home with pretty much the same result.

Would this be indicative of an issue with the mac itself, or is it compatibility with newer screens? -> Is it worthwhile to get an older or lower resolution display?
Any recommendations on what you would try for this?
I've tried with other types of adapters (DVI to DisplayPort, and DVI to VGA) but only the DVI to HDMI seems to output any video at all.

Thanks in advance for all the help!

Offline GaryN

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Re: No video shortly after boot on Mac Mini G4
« Reply #1 on: January 08, 2024, 02:18:04 PM »
You didn't say but I'm assuming you have a Mini with DVI only.

Wild guess: Open it up and identify the graphics card. Make sure it's an ATI 7500 or better.

Offline aBc

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Re: No video after boot Mac Mini G4
« Reply #2 on: January 08, 2024, 03:34:15 PM »
There is no graphics “card” per se in the G4 minis.
It’s an on-board situation that came w/ Radeon 9200.
Either with 32 or 64 MB of VRAM.
(The 1.5 GHz G4 mini has 64 MB.)

Many HDMI adapters are finicky at best.
With these minis, perhaps even more so.
Skip the Philips 275E unless it also provides
DVI or VGA (with adapter dongle) connections.
But if it does… I’d still test a different monitor.

Now, anyone successfully running HDMI
…to such a monitor should chime in here. ;)

I use many varieties of DVI & VGA monitors
here with various G4 minis. No problems.

Offline GaryN

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Re: No video shortly after boot on Mac Mini G4
« Reply #3 on: January 08, 2024, 09:27:55 PM »
There is no graphics “card” per se in the G4 minis.
It’s an on-board situation that came w/ Radeon 9200.
Either with 32 or 64 MB of VRAM.
(The 1.5 GHz G4 mini has 64 MB.)

Many HDMI adapters are finicky at best.
With these minis, perhaps even more so.
Skip the Philips 275E unless it also provides
DVI or VGA (with adapter dongle) connections.
But if it does… I’d still test a different monitor.

Now, anyone successfully running HDMI
…to such a monitor should chime in here. ;)

I use many varieties of DVI & VGA monitors
here with various G4 minis. No problems.

You know, I have no idea why I typed ATI 7500. It must be the risk of trying to multitask with declining numbers of brain cells. Sorry about that.
I DO know the Philips 275 has HDMI, DisplayPort and VGA inputs.
It would seem however, that the basic DVI > HDMI connection works since the apple startup screen appears. It sounds more like the resolution is changing after that and the monitor isn't following along.

QUESTION rbdr: Have you tried unplugging and re-plugging the monitor after the pic drops out? The objective would be to force the monitor to re-detect the input signal and sync to it. If it works, you'll have a clue as to the problem and can make a decision about which one sees the inside of the trashcan. If it doesn't, you may just have a defective DVI>VGA adapter because that should at least deliver a shitty pic if it works at all.

I'll cross my fingers for you, because the next guess is the ghost of Jobs is messing with you just for fun…

Offline rbdr

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Re: No video shortly after boot on Mac Mini G4
« Reply #4 on: January 09, 2024, 05:37:13 AM »
Hi everyone thanks for the quick responses!

I think I will give it a go with other monitors and will consider replacing the philips at some point.

QUESTION rbdr: Have you tried unplugging and re-plugging the monitor after the pic drops out? The objective would be to force the monitor to re-detect the input signal and sync to it. If it works, you'll have a clue as to the problem and can make a decision about which one sees the inside of the trashcan. If it doesn't, you may just have a defective DVI>VGA adapter because that should at least deliver a shitty pic if it works at all.

Good idea, I think you're right about this being related to some resolution change, as video does come out when using OF or the boot selector. Unfortunately that didn't do it: from what I read in other posts it could be related to supported resolutions + pixel clock speed? (I have no idea how that works or how to calculate it, but sounds plausible).

Regarding the VGA input it might be my monitor as much as it is the cable, I'll have to try on another monitor and report back. Depending on the results I might have to either replace it or have a second one.

Thanks for all y'alls help