To rule out or at least nail down what is going on, you might try some sort of very temporary "extreme cooling", like a giant (human room) fan right next to it blowing on it with the case off, maybe through a funnel tube or something else insane like that.  Anything to see if it is stable once cooler.

You'd want to make sure it IS the gpu, and not something else, maybe more easily fixable, before going further.  It could be anything, maybe even general heat melted something slightly loose.

I love my tibook, but they are relatively fragile or at least finicky machines.

I put an SSD in mine, and afterwards had similar behavior, but found it was...probably?...just screws too tight?  Shielding somewhere touching something?  Who knows!  Regardless, it is stable now, I knew it was something super goofy, that I had done, but never nailed it down.

Wishing you luck!

Chimes
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Yep gfx issues i guess

Also tested on a second monitor via dvi

Repasting? What can fix a tibook gfx card?

„ 867 MHz (introduced Nov 2002) uses the ATI Mobility Radeon 9000 GPU. This chip is known to develop graphics issues due to heat and age — especially solder fatigue under the GPU (BGA).“

Thanks for your time and effort on this; it's truly a great effort. I'm going to read it again to thoroughly analyze all the information.

I'm looking forward to seeing a simple comparison with the copper heatsink.

Like

Thanks for the replies.

The truth is, I can't dedicate myself to manufacturing and selling. I don't have the time, and for it to be interesting, the price would have to be reasonable, and to be profitable, the price shouldn't be. This is something that should be done by oneself, but I need to think about the best distribution method.

So far, it's worked on all the graphics cards I've tested it on, but I should mention that depending on the resolutions supported by the monitor, the control panel displays different or different resolutions. It doesn't seem to communicate equally with all displays, but that may be due to the ADC protocol and not the adapter. In reality, the adapter doesn't convert anything or modify anything; it simply wires the ADC pins to the HDMI and USB pins. If any graphics card or monitor has problems with this adapter, I suppose it would have also had problems with another external adapter.

As for making an external adapter, that wasn't my initial idea. Besides, I wouldn't be able to get ADC connectors, and we would need +5V, which would have to be "snatched" from a USB port. If a Mac already has few USB ports, it's not a good idea to remove one for the adapter.

P.S. @diehard, changing the subject, do you happen to have a link to that OS9 image compatible with the 1GHz iMac G4? I haven't been able to find it.

PART TWO

tl;dr version?

When you renew the heatsink paste in your G4 Mac mini… also change the thermal pad under your GPU. Ya gotta take the mobo out anyway to remove the heatsink. I used .5mm Gelid GP-Extreme. 120mm x 120mm from Amøzon for around $12.00 - and that’s more than enough to replace the pad in 7 or 8 minis. Of course there are other manufacturers, so your results may vary. AND Wozniattack was correct… your temps will rise as the new thermal pad should conduct heat some mo better.

There, now you needn’t read any further.
Just change the pad when you change your paste. Easy!

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Still reading? Be prepared for a great big nothing-burger. You have been warned. It wasn’t enough for me to take Wozniattack’s (and other’s) guidance on this. Oh no, I had to test for myself and if you’re still reading, you can also enjoy in all of the non-fun.

I needed to establish a baseline from which to compare “before and after” results. And instead of using Dungeon Siege, I just ran Cinebench 2003 from start to finish 5 times (30 minutes) because not everyone can easily obtain Dungeon Siege.

Wozniattack previously noted his change from 41.2˚C to 43.3˚C [106.16˚ & 109.94˚F]. A rise of +3.78˚F when playing Dungeon Siege… and after changing his GPU thermal pad. Not all that much difference, really. Right?

Previous wind / air speed measurements were obtained by placing an anemometer right up against the exhaust air vents and without a monitor attached. Well, I needed a monitor attached, on and under a load of sorts, for these tests.

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Et voilà… ye olde “Exhaust Air Temperature Duct”.
Now if your eyes are already glazing over, read no further. Still reading? Then onward….

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Comparisons between previous wind / air speed measurements and using the Exhaust Air Temperature Duct? (Both below with old GPU thermal pad in place… but with relatively fresh heatsink paste.) A little warmer on the right, but compare the recorded Air Speeds. I chalked up the reduced speeds to the distance from the mini, via the duct. Still usable for intended purposes here.  The temperature differences seem more pertinent, odd as they might be. Maybe partially the result of having a monitor attached and ON? Thermocouple temperature probe still in 5th vent from the left.

Also to consider, left numbers from tabletop flat mini. Right numbers from a mini placed up on #303 cans. (4.625” tall.) Ambient temperatures? 68.1˚F vs. 73.8˚F

           

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And now for the really fun stuff. You like numbers? Here’s some more…

             
Top two in the grid are from running Cinebench 2003 for 30 minutes with the old GPU thermal pad. Bottom two are from running CInebench 2003 for 30 minutes with the brand new GPU thermal pad.

I would have thought that the GPU temps would have been higher, instead of the Exhaust Air Duct temps? Keep in mind temperature and air speed fluctuations during the tests. There are more pics attached below.


 Again, all tests performed here with good ol’ #5B 1.5GHz Mac mini and its spinning 80 GB HD. No changing it during all of these tests. And now only one more tear down & setup for the long overdue copper heatsink.  (Maybe another big juicy nothing burger with a stock mini.)

You still reading? If so, don’t fail to check out the attached black & white images below.
Best viewed in the following order… OTP4.png - OTP3.png (Old pad) and NTP4.png and lastly… NTP3.png (New pad).

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Maybe this should have all be posted under “Video”?



 Speaking of variances and fluctuations… check the 2.9s red-circled above.
 (And now that’s all about a week of my life and for what real gain?)

Content… brothers and sisters. Content.

AND the fact that if you expect to place high demands upon your G4 mini / heatsink paste and GPU thermal pad it - while you’re at it. Because simply cleaning out the accumulated dust is not Refurbishing it. A baked (yet “upgraded”) mini can still be a dead mini, “as is”. In just a very short time. Just push it a little hard, me mateys.

The PCB should work on any graphics card with an ADC.

that´s what i wanted to hear.

the experience of people using ADC->DVI->HDMI adapters seem 50/50, in every other case it does not work because of either the monitor, the cable, or the adapters.

so your board could be the definitive answer for the general problem? what about making it an external adapter instead of soldering it to the card? (or is that a problem bc it requires power at a voltage not contained in the graphic interface?)

The going rate for an untested one on eBay these days seems to be about $40-$60. Tested ones go for $80+ especially if with accessories.

Zacly!

If anyone is selling mini G4s for 20 euros still, please let me know because I'll buy them from you! The going rate for an untested one on eBay these days seems to be about $40-$60. Tested ones go for $80+ especially if with accessories.

I will try to at least load a temp program on one of my 2 month old M2 Pro minis;  I am testing my ancient external MIDI gear with the newest version of logic.  I bought (2) M2 pro minis, because Best Buy was blowing them out @ $599 brand new for:

Mac M2 Pro mini with 16GB and 512GB SSD

So, I went from a Mac Pro 6,1 with 64 GB and 4TB NVMe to the silicon... I think they blew these out since they knew the M4 mini would be the favorite in 2025, but the M2 Pro, IMO, is better for audio, with more ports, running cooler, and a better form factor.  So the mini with and external dock that literally fits right under it, cost me $699.  It runs silent, I mean NO noise whatsoever and ice cold, no heat anywhere on the outside after 2 hours of runtime.

Internal SSD Reads and writes at over 3000 MB/s, and the NVMe in the bottom of the dock reads/writes at about 900 MB/s.

The PCB should work on any graphics card with an ADC.

Since ADC adapters are literally $200 on eBay in 2025, this adds some amazing un-tapped functionality to all these old video cards.  There are so many users that have given up on their trusty ADC monitors over the last 10 years, and this is the ticket to add dual screen ability back to those who transitioned to a large single screen LED and look at their "unused" ADC port as a dead appendage.

Awesome job !