iMac G3 (Slot Load) ATX conversion - Resolution Problems?

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Joined: Jun 29 2005
Posts: 2

Hello everyone,

First post here. I bought a 400mhz iMac DV (slot loader) off eBay for $40 for my son to play with. Well after 2 weeks the flyback transfomer died so I went ahead and took the logic board out to do the ATX mod. So now the logic board powers up just fine, and I can get into OS X. My problem is that I am using an external monitor, but the resolutions in OS X only go up to 1024x768 (the original iMac resolution). The picture looks fine, but on a 19" LCD monitor, I would like to have a higher resolution. When I try it with a 15.4" widescreen, the monitor tells me "mode not supported" probably because the refresh rates. I made a custom cable to hook a VGA port to the 20pin video connector on the bottom of the logic board. Have any of you been able to get better resolutions in OS X with a slot load iMac logic board? Thanks for your time.

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Offline
Joined: Sep 3 2004
Posts: 170
try SwitchResX that sometime

try SwitchResX
that sometimes works

ive done that mod, and the monitor i use is a 15 inch, so 1024x768 works 4 me

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Joined: Jun 29 2005
Posts: 2
Yea I've been trying to use S

Yea I've been trying to use SwitchRes X, but everytime I try to type in custom timings, it brings the number back to "0" after I move to the next field? What am I doing wrong? Thanks again.

Offline
Joined: Jan 20 2005
Posts: 700
refresh rates

i think the reason your LCD 15.4 inch doesnt work is because of the refresh rates the Slot load uses, for me, i used an old multi scan 15inch and it would only display at 1024, anything lower would cause it to scramble badly. so your 15.4" might not refresh as high as the imac at lower res...

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Offline
Joined: Aug 3 2005
Posts: 1
ATX conversion?

Where did you get the info for the conversion? I have just recived the same imac with the same problem. I would love to make the conversion. All I hav been finding info on is the older models. any help you could offer would be great.

tmtomh's picture
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Joined: Dec 20 2003
Posts: 568
Refresh

I would tend to agree with the other folks about refresh rates. I can't remember the exact figures, but I do recall taking note of the extremely high refresh rates of the slot-loading iMacs (something crazy like 117Hz at 1024x768).

So it could be that. Or it could just be that something in the video hardware simply doesn't support anything above 1024x768.

Matt

Reverend Darkness's picture
Joined: Dec 20 2003
Posts: 502
ATX conversion?

I, too, would appreciate any info on the conversion you could offer...

My company has six slot-loads sitting around acting as doorstops.

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