Wednesday, July 6, 2011

My Dream Setup - iMac G4 and G5 - Dual Monitors

The iMac G4 "mac mini monitor"
Although this has been a great hobby for me, my goal has always been to produce a computer and setup which allows me to use the form factor of the iMac G4 with modern hardware and the Mac OS.  As you can see from my summary, most of my mods - besides the black iMac/VESA - have been disassembled for parts as I feel that the mods have gotten better and I simply don't have use for that many iMac G4 hacks.  The fact that I have completed a 20" all-in-one iMac G4 complete with ports and a blu-ray drive using the ECX core 2 duo board shows me that this mod is doable. The only negative is problems with snow leopard (and presumably Lion) with this board.  However, there should be no compatibility problems with the new Sandy Bridge KEEX-6100. Still, I have expressed my reservations with hackintoshes in the past and I would prefer a true mac.  So while I have been using my touchscreen iMac/Cinema Display mod with my old mac mini, I have really come to prefer the appearance of my newer mod, the native iMac G4 all-in-one mod.  So after filming a video of the all-in-one mod and much deliberation, I decided to disassemble this mod and "switch" this mod with the apple cinema display one.  Thus, I will get the benefit of a brand new/white exterior and the native housing which makes this completely indistinguishable from the original iMac G4.  I will however loose the touchscreen.  I simply felt that this came closer to what I originally set out to do.  For myself I do not mind the small footprint of the mac mini being on the desk as well.  Plus, this leaves open other possibilities such as using it as a desktop monitor for my Macbook.

Two Ports: DVI and Power
I did decide to make one additional switch.  Although the mod works fine with the original iMac G4's LCD - the apple cinema display's LCD has a better contrast ratio, viewing angle, brightness, and response time.  I had an extra apple cinema  LCD (which was intended for the mod detailed later in this post that I ended up not needing).  So I replaced the iMac G4's LCD with the Cinema Display's.  Here you can see photos of the new iMac G4 hooked up to the mac mini and apple pro speakers via the iFire adapter.


From the back
 I left out the bluray drive (as Mac does not yet support it), but now have plenty of room for the power brick which is now included internally.  So only a DVI out and C14 Plug is required on the back.

iMac G5 with Cinema Display Cable
My ideal setup has multiple monitors.  Unless I have a 27" screen - I find having the extra screen real estate important for multitasking.  At first I considered two iMac G4s but thought that may look odd.  So I decided to add my second favorite iMac design of all time - the iMac G5.  I obtained a broken 20" iMac G5 in good cosmetic condition and removed all but the lcd itself.  I had an extra apple cinema display with a broken screen - I put the cinema displays components around the native iMac G5's lcd (which luckily still worked) and I now have an external monitor in a G5 shell.  For now I just wired the cinema displays cable out the back where the C14 plug used to be.  There are still some issues to work out such as the monitor now being very light.  Also, the screws in the bottom no longer fasten into anything.  And, I do plan on wiring the 2 USB and Firewire 400 inputs of the Apple Cinema Display to make them accessable on the rear panel of the G5.  I know I did not go into detail on this mod - as there really isn't much to it.  Just know that the native iMac G5 panel works with a cinema displays controller board.  If anyone is interested in this, please let me know and I will add a step by step and parts list.  And if you are wondering why I didn't use the TMDS to DVI hack, its because I would still have to power the iMac G5's inverter which also requires a 24V line.  Sure, the iMac G5's power supply could be altered, however, the power supply on this was broken and I had the cinema display components.

On the 20" iMac G4
Unfortunately, my mac mini does not support dual monitors (the current one does).  I am hopeful of a new Sandy Bridge mac mini which will be the centerpiece of this setup.
So first the iMac G4 connected to the mini.

On the 20" iMac G5
Then the iMac G5 connected.  And hopefully in July...Both!










As always comments, questions, and suggestions are appreciated.  Thanks for reading!

22 comments:

  1. As always... a great post.

    I will be waiting for the good news this July.

    Any chance of modding more mac G4s similar to the above. I'm thinking of buying one from you


    Cheers

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  2. Hey Carl - thank you very much. To be honest I really wouldn't want to get into selling. The cost of the parts is very high and it's very labor intensive. And things do break - the electronics are older. The CCFLs, inverters, and controller boards come from equipment that's about 5 to 10 years old. Plus - I am certainly no professional, I've made poor solder joints that have broken and required repair. My point is for the amount of money I would have to charge I would feel terrible if something broke in the first few months of use and I don't want to get into servicing broken mods.

    That said I would be happy to help you if you wanted to attempt any of these mods. I have talked several people through it who have minimal electronics experience both with getting the parts and the assembly. In certain circumstances I may be able to help with small parts of the project such as prepping the neck, some wiring, soldering etc. Take care and thanks for reading.

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  3. Hello,
    also from me congratulations to this mod and the video. You are absolutely right with your comments to the heat issue inside the dome. In my mod I decided to use an Atom N270 board but without any cooler. The dome also contains a Slot-In-DVD and an SSD. After several hours of working with the mod, the neck is warm (but not hot) while the CPU itself stays at 60-65° Celsius. I also decided not to integrate the power supply into the dome (It's only one power supply here with the display connected by LVDS) So in my estimation your ECX solution is the only way to integrate a more powerful CPU. So I am very interested in your progress with the new Sandy Bridge ECX board.

    In the meantime I will perfect my knowledge in upgrading displays from CCFL to LED. Recently I have constructed a "converter" for a 20" ACD that allows changingthe brightness from within the system preferences of Mac OS.

    Cheers, Frank

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  4. Frank, thanks for letting me know. I again have heard the same thing from others. Lets face it you would never choose a thick steel cage with only a few holes poked in the top as a computer case if you had the choice. Every other cooling solution including water cooling that I could think off adds even more bulk to the base. I'm not sure the "convection" cooling that was originally used would be effective with modern processors even if it could be reproduced. That said, I too am hopeful the sandy bridge ecx board will be effective and fingers crossed - reasonably priced.
    Excellent work with the converter, how did you manage that? Brilliant work as always. - Jon

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  5. Concerning the Converter: it took me some time to identify all input connections of the original 20" inverter, but I found a replacement where they have figured out the layout. This inverter runs on 25V, but also uses a +5V line as a power supply for the electronics. The brightness is controlled by a 0..4.8V line (with 4.8V=dark). This is a perfect input for a cheap TL494 PWM control circuit, which is connected to a BUZ11 Power MOSFET Transistor. Together with a 3.5V line, which indicates if the display backlight should be on or off, that's all I needed.

    The original inverter provides a special feature called backlight control. There are two lines coming from the logic board that must be connected to ground, otherwise the standby led will flash to indicate a backlight failure. That was the reason why I dived deeper into that inverter stuff :-)

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  6. Dear JBerg

    Ever since i bougth an (defect - display not working - only on an external monitor) Imac g4 20 - just because they are so nice - Following your mods whitch are quite interresting. i'm looking for a lcd to power up my Imac g4 again. Because you have a lot of experience in modding Imacs i'm asking you: is it possible to equip the Imac g4 20 with a lcd form a Imac g5.
    (Imac g4 lcd 20"screen are hard to get).

    Luuk Sollie

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  7. Luuk, even through the standard iMac G4 LCD is made by ID Tech, while the iMac G5 uses an LG LCD, they are interchangeable. The use the same TMDS converter and pinout, so you should not have any problem using a G5 screen.

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  8. I am curious if there is room in th G5 for a mini itx board??

    Soon I will gut my iMac G3 slot loader and place an LCD panel and mini ITX in it. Hope I can find a slot load DVD writer for it too

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  9. Mark - If you get a low profile fan/board, it would likely fit into the first generation iMac G5. However, the iSight version is substantially thinner and I do not believe any itx board would fit regardless of how thin.

    Cooling however may be a problem, a passively cooled, low-power board is probably the best bet.

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  10. Congrats man, i was looking for this for a long time and you certainly are the best modder i've seen.

    But i have a question, the dvi cable of the cinema display goes through the imac g4 neck?

    Thanks

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  11. John, thank you. Not quite, i extended the wires which are TMDS (same signalling DVI uses) that connect the LCD and the controller board. I used 2 gray cables from the iMac G4s neck with the TMDS signaling wires from the cinema displays DVI cable. So some wires are part of the DVI, some go to the controller and then the controller gives off wires that join the DVI cable of the cinema display. I really like this method, but it is more complex than my current 20" method which requires no neck modification. Hope this makes sense.

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  12. I would like to convert an iMac G5 20" that I got from a family member (which I wiped) into a second display for my MacBook Pro (early 2011). How would I go about doing this?
    CG

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  13. Whoops sorry, G4.
    CG

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    Replies
    1. At the top of page(right below the blog title) there are tabs click on the Guide: 20" iMac G4 Tab. Follow guide but don't put a computer in the base, stop at the dvi connection.

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    2. Thanks! I found that right after I posted the comment.
      CG

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    3. Hmm- there is no DVI port on my G4. Why is that? And how can I get a signal out otherwise?
      CG

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    4. When you say signal out, you mean get a signal to the monitor from a different computer source, right? There is a mini-DVI port but that is for sending the image from the computer in the base to a different monitor.

      The reason there is no "Signal In" to the monitor is really the whole point of this mods, you have to make one.

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  14. A new comment to an old thread...

    I have a 2006 Intel iMac 24 that looks identical to the G5 you have pictures of above. It has ceased to function, but I'd like to re-use the display as a desktop display for my MacBook or my still-functional PPC Mac Mini. Assuming that the display in the Intel iMac and G5 iMac are indeed identical, it appears that I would need to obtain the controllers for an Apple Cinema display to be able to convert the input for display on the iMac screen. Is there any chance that the offer for a step-by-step and parts list still stands, four years hence? Can I piece together what needs to be done by reading the G4 blogs more thoroughly?

    Thanks for the great information and inspiration.
    Kevin

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    Replies
    1. Hey Kevin, unfortunately, apple changed to LVDS when they went to Intel processors. Otherwise, the LCDs are indeed identical. The PowerPC LCDs used TMDS (the same type used by HDMI and DVI). Though, this is a little but on oversimplification, because the PowerPC LCDs actually used a conversion board that was inside the monitor itself. This is what allowed me to use HDMI/DVI to connect directly to the monitor. So, you can use your LCD, but you will need a video processing board to convert HDMI/DVI, VGA, or Displayport (whatever incoming signal you want to use) to LVDS. These are made by several companies and can usually be found on ebay.

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