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dwnldr

macrumors member
Original poster
Jun 22, 2016
46
17
Slovakia
Dear Friends,

i have old MiniG4 which is used as iTunes server. The Mac is connected to Philips TV via DVI to HDMi cable, if i need to manage something directly, not via Screen Share. The main problem is, that after reinstalling OS X 10.5. i need to change the resolution (Hz rate) to 24Hz (1920x1080x24hz) because otherways is the resolution not fully recognized by the TV, the screen is flickering. This same happens during 10.5 installation. So it is a painfull and very long procedure, sometimes impossible (mostly done with external monitor, which doesnt exists anymore). Is there some option to change the resolution during installation of OS ?

Thank you !
 
Is your TV a 4K TV?

If so, it might be worth investing in a 4K HDMI cable. I recently did that and flickering and artifacting for different resolutions disappeared and allowed me to drive the max resolution on my 4K TV.
 
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eyoungren, thank you for reply! No, it is 1080p TV. The screen looks perfect after i set in OS X the right 1920x1080x24Hz resolution. Sadly, the installer runs on other resolution/hertz rate and the screen is "destroyed"
 
eyoungren, thank you for reply! No, it is 1080p TV. The screen looks perfect after i set in OS X the right 1920x1080x24Hz resolution. Sadly, the installer runs on other resolution/hertz rate and the screen is "destroyed"
I'd try a 4K cable anyway just to see what happens. There's a Walmart brand called "Blackweb" which I've been using. It's a braided cable and does pretty well. The most I've ever paid was $15 and that was for a 12 foot cable. The normal 3-6ft cables were about $8.

At the worst, you'd have a spare cable.
 
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I’ve seen my Mac mini G4 exhibit issues with different displays which my other PowerPC Macs will work fine with. It has resulted in garbled output over HDMI on my 4K TV or half an image on a 1280x1024 19” display (circa 2004) over DVI. Switching resolutions down has helped, but I think the Radeon Mobility 9200 GPU in the mini must have some frequency bugs which were never ironed out.

That being said, I don’t know of a method to change the resolution from the installer. I would recommend you drop into Firewire Target Disk Mode and hook it up to another Leopard compatible Mac. Boot the other Mac from the installer disc and install onto the mini’s HDD.
 
I’ve seen my Mac mini G4 exhibit issues with different displays which my other PowerPC Macs will work fine with. It has resulted in garbled output over HDMI on my 4K TV or half an image on a 1280x1024 19” display (circa 2004) over DVI. Switching resolutions down has helped, but I think the Radeon Mobility 9200 GPU in the mini must have some frequency bugs which were never ironed out.

That being said, I don’t know of a method to change the resolution from the installer. I would recommend you drop into Firewire Target Disk Mode and hook it up to another Leopard compatible Mac. Boot the other Mac from the installer disc and install onto the mini’s HDD.

indeed the Mac Minis Radeon 9200 (its not a Mobility part) has a Buggy DVI TMDS transmitter that cant handle high TMDS frequencies

and due to how stuff works 1080p actually has a higher TMDS frequency then 1920x1200 of say a Cinema display, the TMDS issues on the 9200 was patchable via a ROM update which the Mac Edition 9200 did get but the Mac mini never got one.
 
Thank you very much for reply !

As i told, the problem is solved immediatly after OS X is installed, and choosen 24Hz or 25hz refresh rate on 1920x1080 resolution. The harder part is to install the system. Choosing the right boot media is also a "blind" procedure, also like installation. I think the default refresh rate is set to 50Hz or 60hz and regarding to DVi-HDMi-TV connection is the resolution set to 1920x1080. That is the trouble... The Mini is with AirPort, storage "build hidden" under the TV rack for "touchless" use. Therefore will be great to find some solution to this. It is clear, that reinstalling is not an daily thing, but if is everything nice connected-wired, it will be sad to disassembly everything for 20minutes work...
 
Couldn't you make an image of the installer Cd/DVD and change some simple plist's and burn it again ? I really don't know what I'm talking about...don't be too hard with the comments.
 
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phil - The installer is stored on local HDD. I created extra partition for installer, because the DVD drive is swapped to HDD. So i can easily change .plist and try immediately. However, i find some infos and made a try with plist editor to force resolution in :

com.apple.boot.plist

<key>Graphics Mode</key>
<string>1920x1080x24</string>

But nothing changed... So i don't know, if i made something wrong (test, position in plist, or what...) or the last "24" number is for Color depth and not for refresh rate. I need to force refresh rate to 24-25hz...
[doublepost=1540118402][/doublepost]Painfully i find the "August 2005 ATI Radeon Universal ROM Update". This should be the best and original solution - This should install newer ROM. The original rev. is 113/116, the newest is 2xx... But, there is a sign in the installer, that the FW will be not upgraded on OEM machines (iMac, MacMini etc....). SO, the installer runs correctly, but nothing updated :(
 
phil - The installer is stored on local HDD. I created extra partition for installer, because the DVD drive is swapped to HDD. So i can easily change .plist and try immediately. However, i find some infos and made a try with plist editor to force resolution in :

com.apple.boot.plist

<key>Graphics Mode</key>
<string>1920x1080x24</string>

But nothing changed... So i don't know, if i made something wrong (test, position in plist, or what...) or the last "24" number is for Color depth and not for refresh rate. I need to force refresh rate to 24-25hz...
[doublepost=1540118402][/doublepost]Painfully i find the "August 2005 ATI Radeon Universal ROM Update". This should be the best and original solution - This should install newer ROM. The original rev. is 113/116, the newest is 2xx... But, there is a sign in the installer, that the FW will be not upgraded on OEM machines (iMac, MacMini etc....). SO, the installer runs correctly, but nothing updated :(

Hm... maybe you can try to extract that firmware and flash with graphiccelerator :)

9200 should be supported
 
if you want to brick your machine sure, the PCI Radeon 9200 Mac edition ROM is not compatible with the Radeon 9200 in the Mac mini G4, for one the Port layout is completely different

(im not even sure if Graphiccelerator could flash a Mac mini GPU since the OptionROM is in the main SystemROM rather then on a separate EEPROM)

your best bet for getting round the TMDS issues in this case is put the Mac mini G4 into target disk mode, and if you can, image an OS directly to its HDD via another mac. (with screen sharing enabled so you can remote into the install on the G4 and drop the screen rez or freq down to reduce the frequency on the TMDS transmitter)
 
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Thank you very much for reply !

Sadly, the only solution was connecting external monitor.
The connection must be via VGA, because via HDMi was the result on the monitor the same, as on TV = no picture... The hardest and longest part was the upper mentioned disassembling from the place. Now is OS reinstalled, resolution set again to 1920x1080@24Hz and the picture on TV is back again. Mac is configured for unattented use, but can be "touched" via Screen Sharing or mentioned TV. I didn't find any other solution.

Greetings

Ronnie
 
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