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Zim · Jan 2, 2005, 06:39 PM

How hard would it be to use the CRT from the old g3 iMacs?

I have 2 friends, both with a 233?300? iMac g3, both of whom are very much hoping Apple does come out with the headless cheap-Mac this week... they already have a functional 15" CRT in the existing iMacs.. any way for them to hook up to it?

Thanks,
Mike

sine -''-..- · Jan 7, 2005, 04:47 PM

Hey thats an awesome idea... You can easily do that - if its the gen A B or C imac, you can just pop off the back cover of it and you'll find a standard mac 15 pin cable coming from the internal monitor. So you could adapt that to standard SVGA and bango. Stick the pizza box under the imac and nones the wiser.

f1000 · Jan 8, 2005, 12:07 PM

There are some potentially hazardous voltages around a CRT and its associated caps, so please be careful if you do mess around in there.

sine -''-..- · 07:02 PM

Originally posted by f1000:
There are some potentially hazardous voltages around a CRT and its associated caps, so please be careful if you do mess around in there.

un unh... not in an imac... see if you look at this picture: http://karen.collapsar.net/imac/the_...of_an_imac.JPG
[Moderators are not exempt from the inline image rules. --tooki]
you'll see what i mean... that cable dangling out the left, its the monitor cable... you can pull out the whole logic board and you'll have whats there... and then you can turn that logic board you pulled out into: iRack

f1000 · Jan 10, 2005, 01:14 AM

Point taken, sir. Carry on.

Zim · Jan 10, 2005, 10:45 AM

Originally posted by sine -''-..-:
Hey thats an awesome idea... You can easily do that - if its the gen A B or C imac, you can just pop off the back cover of it and you'll find a standard mac 15 pin cable coming from the internal monitor. So you could adapt that to standard SVGA and bango. Stick the pizza box under the imac and nones the wiser.

I'm more than willing to solder at the smallest level, and hack cables, PCBs to no end.. but I've never messed with video cables much... so could you point me to a little more info on this?

Are you saying that the 15-pin connector here, contains the same 15 pins that are on a normal Mac VGA connector?.. I just need to make what I'd call a "wiring harness" (if I were installing a car stereo)...

Thanks,
Mike

sine -''-..- · Jan 11, 2005, 01:46 AM

naw man, you just need one of these

ta da

make sure it goes the right way... that is, DB-15 Female to HD 15 Male. Note that they are much less common then the other way around. (like this - NOT what you want)

This is all true, of course, only if the new box has a standard pc svga port... which I assume it would.

Oh - and the dangly cable that comes out of the iMac will probably be too short, so you'd need to get an extending cable in between, or make one... whatever.

sine -''-..- · Jan 12, 2005, 02:23 PM

Right - So they'll need one of these adaptors like I was saying... but thats it!

Zim · Jan 13, 2005, 06:25 PM

Eggsellent... many thanks for the info!

Mike

Eriamjh · 08:52 AM

It will work, but how will you turn on the power to the display?

Normally, the power button fires up the mac, but since you just want to drive the display, how will you turn it on?

I supposed you could just let the internal mobo boot up without a display and then push the power button to turn it off, but there must be a more elegant way of ONLY driving the CRT from the iMac's internal PSU.

smic · Jan 23, 2005, 08:52 PM

ok i did this with my 266 imac last year and it never worked for me
heres what i did
i was using a 17inch studio display for my imac, and the imac moniter was not used

then i picked up a cheap pc and thought i could use the imac moniter for the pc

so i had the imac on, with the 17inch display, and plugged the pc into the imac moniter
it didnt get a signal, so i tried restarting both of them, still nothing, power off and power on together, and the most i got was the screen turning on with the power, but not powering up

so i dont know if i was doing something wrong, or if there is more to the imac moniter to make it work

Predsr · Feb 5, 2005, 05:09 PM

has anoyone had luck with this?

Waragainstsleep · Feb 10, 2005, 04:36 PM

If you want to use the CRT from a later iMac, you need the pinouts for the cable which connects the display to the logic board. This site has the pinouts for the female end (on the motherboard), so you'll need to flip or mirror or whatever to get them the right way around.

http://www.ct-scan.com/iMacATX/index.html

macgyvr64 · Feb 25, 2005, 01:49 AM

Originally posted by Eriamjh:
It will work, but how will you turn on the power to the display?

Normally, the power button fires up the mac, but since you just want to drive the display, how will you turn it on?

I supposed you could just let the internal mobo boot up without a display and then push the power button to turn it off, but there must be a more elegant way of ONLY driving the CRT from the iMac's internal PSU.

On ATX power supplies (which I believe the iMac's is..or is close to), you can short two pins, and it stays on as long as the two are connected. Green to ground, if I remember correctly. That just might do it.