Mac OS 9 Lives
Mac OS 9 Discussion => Hardware => Topic started by: G4 MDD Steve on May 13, 2026, 11:58:21 AM
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Hello, I've just dug out of storage and attempting to resurrect a 2003 MDD 1.25 single processor G4.
I've bought new RAM (2x 512Mb), a new clock battery, reused an old 640Gb iMac HD with an adapter card. The monitor is connected with a DVI to DP cable. When I turn it on I hear the chime, which suggest the motherboard is OK, but the monitor does not detect an input signal, so I see nothing. I was expecting the flashing question mark for no OS present.
Is there a fault-finding sequence I could follow to narrow down the problem? I know the monitor is OK because I used it on my Raspberry Pi, which I just sold. So, to me, that suggests the video card or the cable, which is brand new. The card is the 64Mb version
Any help appreciated.
Steve
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Some DVI-DP cables are one side only, i have cable that can only be used to connect dvi monitor to DP
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Oh, thanks. Would you recommend DVI to HDMI?
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A quick rant regarding “standards”.
In the beginning (lol) cables/connectors were described based on the direction of signal flow. So, if your computer had a DVI OUT and the monitor had a DP IN, the cable would be a “DVI-to-DP”. All good, right? It seems however, that somewhere along the line, the logic got reversed so that the cable is now described as “this cable connects device to” so that it’s backwards.
A “DVI to DP” cable NOW means the DVI is the destination (the monitor) and DP is the source (the computer) to connect a DVI monitor to a DP computer.
So, it’s likely that your cable is connected backwards from the way it is supposed to work and that’s why there’s no signal on the monitor. There’s stuff inside the connector to enable the process so it will only work in one direction.
You described everything except the make/model of the monitor. That might be useful info.
Your last post seems to suggest that the monitor might also have a HDMI input. If you go looking for a “DVI-out to HDMI-in” cable, you’ll immediately notice that most of them will say they’re bi-directional. That’s because an HDMI monitor-in can be directly connected to a DVI source if you just get the correct wires on the correct pins.
So, that’s probably a good thing to try.
Ain’t this fun?
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You're absolutely right, the cable was sold DVI to DP, which I assumed was what I needed. If the retailer can't exchange it I'll get an HDMI cable.
My monitor is a 19" Lenovo with 3 input ports, HDMI, DP and VGA
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I'm going a bit mental.
I'm on my third cable now. This final one is specifically a bi-directional DVI to HDMI, but still no video out. It chimes, the fans start up, everything seems normal, except no video.
I took a picture of the boards while running and noticed a red LED, but I'm not sure if this is normal or not? My next stop is a new graphics card, which I don't really want to do as this is a practically a zero budget build.
Can anyone help?
Cheers
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No mention of what exact video card is present.
Can you try a simple VGA connection to test output?
AND, what OS are you now running on the MDD?
*Also mentioned using an “old” iMac’s 640 GB HD (with an adapter card?). SSD?
If a VGA test connection also yields “no signal” to your monitor,
I’d reformat the drive and reinstall a fresh OS. ;)
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Thanks.
I'm running no OS at all at the moment. The HD is totally clean ready to install OS9, but I can't do that without video. The card is the 64Mb card installed at birth.
The output ports on the standard card are DVI and ADP. I really don't want to buy a 4th cable.