Showing posts with label 20"iMac G4. Show all posts
Showing posts with label 20"iMac G4. Show all posts

Tuesday, May 17, 2011

Update - The Native Inverter and LCD Glass

First let me start off by saying that I did something very stupid despite me writing not to do this time and time again.  I soldered the DVI connector on without putting it through the hole in the dome.  So I had to cut and resolder and for those of you that have never seen the components of the black wire of the imac neck, I can tell you it as an absolute nightmare.  They are composed of 4 wires in which are 3 wires; a red (+), a green (-), and a ground.  The red and green wires have a small plastic coat surrounding a single wire that is the size of a hair. When I set up this initially I had the bottom pins on and was able to use a tiny dab of solder, having to resolder these tiny wires, wire to wire has caused signal problems.  Keep in mind even one failed connection will give you no image whatsoever, so a multimeter is very helpful.  But poor connections or poorly shielded connections will result in color distortion.

That said there is some very GOOD news.  The native LCD for the Apple cinema display (LM201W03) needs to be modified to fit and although it fits, I decided to try the native iMac G4's (IDTech 20.1") lcd glass and it also appeared to work (though until I have a perfect image I can not confirm this 100%).  So it is possible that the only thing you may need is the LCD controller board from the apple cinema display and the cable to get this mod to work as the native G4 inverter has been confirmed to work and the native LCD glass appears to work.  This would be quite helpful as you can use a broken cinema display with a cracked screen.

 To the right you see the mod to date.  The top monitor housing closes as easily as the original as it uses the native inverter and the native glass.  Because I wanted this mod to be as close to the original as possible - I actually purchased a new monitor housing and base cover from ebay as most of the broken used iMacs I have acquired tend to be yellowed or scratched.

You can see the monitor from the front, side and back.  To the right of that is the lcd controller and ECX motherboard.  The ECX boots from a compact flash card located on the underside of the board.

The ECX board is the size of a 3.5" drive.  My plan is to mount the ECX board on top of a blu ray drive in the native drive caddy.  (essentially taking the place of the native hard drive).  As the CPU fan will be sitting at the top of the dome, I will not need a fan, so I should be able to fit Wifi and Bluetooth at the top of the dome with the vent holes.  As I will not be using the native power supply I should have room around the ECX board to fit connectors.  The lcd controller board will replace the native iMac G4's motherboard at the bottom of the dome below the drive.  As its smaller than the native motherboard I'm hoping to have room to wire up some rear I/O ports.  The only downside is that this leaves no room from the power supplies for both the monitor and ECX board.  They would fit in the drive caddy and using a splitter a simple AC plug could be placed in the back, but then obviously there would be no drive.  I have thought about using the native iMac's power supply, but I really need the room and in a similar experiment I fried a different ECX board in the past.

So, I'm going to keep them external.  For one the power supplies are small and this is a desktop computer, it won't be moved that much.  Plus, I have always loved the drive and by using blu-ray it can be useful.  Also, its gonna be tight in there and there is really no cooling system in place - so keeping hot power sources external is probably for the best.

I do think the system is likely to be hackintoshable - the chipset has been hackintoshed before (this is the Quanmax KEEX-4030 ECX board for those interested).  The thing that I have never heard about is booting snow leopard from a compact flash card - a 2.5" or even 1.8" SSD may have to be shoehorned in somewhere if hackintosh is your goal.

Here is the system booting (again notice the small resolution during the boot that I previously discussed).

This is where the frustration set in - with windows booting.  While I previously had a pristine image, after the resolder, the colors are unfortunately off.  A multimeter revealed all intact connections but I was getting some week noise at the wrong pins - so I suspect some interference or crosstalk.  I'm going to remove all the solder joints for the black wires and try redoing them with fresh connections and extra shielding.

To do this mod, I actually used cables from the necks of different iMacs.  There are the black and grey cables that carry the DVI signal, however the apple cinema display has "extra wires".  Some of these probably aren't necessary, but some of them are.  As a result, I had to add an extra grey wire from a different iMac.  I replaced the native LED/Microphone cable with this wire.  The wiring is somewhat difficult to explain.  If I continue to have difficulty with the black wire of the native iMac, I will likely change it to a different wire.  Likely either the equivalent wires from the apple cinema display or another grey wire.  Both of these choices would be MUCH easier to work with.  Either way when I do finalize how I wire the neck, I will post specific instructions.

While I am quite proud of some of the previous mods - this mod is actually much simpler and besides having to push some wires through the neck, a lot less labor intensive than previous mods.  In addition, if it does turn out, as it seems, that either LCD panel can be used, combinations of discarded iMac G4's and apple cinema displays can be used.  I would NEVER tear apart a working iMac G4 and couldn't bring myself to tear open my mac mini to try to fit it in the base.  I even hated even using a working apple cinema display in my previous mod.  Its always great to re-purpose otherwise useless parts.  But whats great about this mod is that there are so many different ways, but this one feels the closest to the native 20" iMac G4 that I've come so far.

Keep in mind that the KEEX-4030 uses the same Socket P Penryn Core 2 Duo chip thats in the previous and current generations of minis.  This ECX board is no slouch.  That said, if there was a problem with it, I think this is the mod that I would open up a mac mini for and try to put it in the base.

I'm hoping to figure out the wiring, clean up the image and start putting the base together this weekend.  But, as always all comments and suggestions are appreciated, but please no comments about seeing windows on the iMac G4 - Its the only operating system I currently have on a compact flash card.  Also feel free to ask any questions.

Wednesday, February 9, 2011

Completed Mod - The 20" iMac G4 / Apple Cinema Display Touch Screen Mod

I am thrilled with how this mod came out.  Not only does it look great, but I really believe that it will stand the test of time.  It is rock solid stable and an absolute pleasure to use.  And to be honest, relatively speaking, the mod was not that difficult.  It can be done in a few days.  For those interested, I can give very detailed instructions.


OK, I wanted to make it this all-in-one BADLY! But, after almost shorting out my itx mobo, I was in no mood to open the mac mini up and put it inside.  That said, the older generation mac mini would likely be superior to the mini itx in terms of fit.  However, the new mac mini is a no-go without serious modification to the internal faraday cage.  For now I am going to keep the mac mini external.  I may revisit this in the future, but for now, I put the power adapter, touch controller, and usb hub into the base.  I was also going to add the griffin powerwave adapter, but am considering trying to track down an iFire adapter (if the price isn't astronomical).  They both power the Apple Pro Speakers. but the iFire doesn't require external power.

Here are several additional pictures:
    The ports on the back are simply a USB (to connect the USB hub), an AC cord (the cinema display power adapter is at the top of the dome), and a DVI.


The 5 wire touch screen cable is still a little but of a work in progress.  I'm confident that Ill be able to hide it under the front bezel, but I am likely going to have to cut into the ribbon cable.  Because I do not want to damage the 20" touch screen, I have purchased, a much smaller 7" 5 wire resistive touch screen to experiment with.  But for now, this works fine.

This mod has really been my favorite so far.  It feels exactly like the original iMac to me, plus the touch screen.  This was certainly not the direction I expected to go when I restarted this project, but am very happy where I wound up.  Again any comments or even constructive criticism would be appreciated.  Thanks again and happy modding!!!

Update: Touch Panel wires hidden under bezel

Sunday, January 9, 2011

Inverter Frustration

After success with the 17" I was hoping good fortune would carry over to the 20" mod.  However, the 20" Inverter has continued to be a problem.  As the DVI/TMDS is essentially the same as the 17" (with just extra power to the panel) I don't anticipate this being a problem.  So the task of turning on the backlights seems simple enough.  Here are the problems and failed solutions I have tried:

The original inverter is remarkably flat  and specifically designed to fit in the monitor chassis. I have not been able to get consistent even lighting.  It does require a 24V line so I am using a separate DC line to power the 2 24V lines. As you can see I have gotten some response.  By giving 12V to the on/off it can become very bright.  But, this is neither stable nor even.  Without a doubt there is some way of mimicking the iMac's signal and use the native inverter.  But, I am not an electrical engineer and the entire purpose is to keep this as simple and stable as possible.  I have thus moved on in an attempt to find another solution.



Aftermarket inverter.  Available on ebay are several relatively cheap universal inverters that can support 6 ccfl lamps with a 4pin and 2 pin connectors.  This one was $30.  I'm not sure if the picture does it justice with the glare, but the screen is evenly lit and bright.  Whats more is that the connections are very simple.  There are two 12V rails, 2 grounds, one on/off - which takes 5V, and an adj/dimmer.  However, while much narrower, it is longer and more troubling, slightly thicker than the native iMac G4 inverter.


I thought it may be possible to make it fit in the case with some alteration using a multi-max dremel.  The back of the monitor housing uses "raised x's fit the monitor tightly.  I thought that by removing these raised areas I may be able to create a little more room for the thickness of the inverter.  As you can see below on one side the "Raised X" has been removed and sanded down (this does not damage the back or outward appearance at all).  I then placed the inverter in at several angles (to try I didn't use the protective plastic covering).

 As you can see it just doesn't fit .  I don't want to press down firmly, screw it in, and leave it under pressure.  I know it may not look like much but it extends around the entire side of the monitor.  As I was hoping to make this a touch screen as well, the monitor is likely to be somewhat unstable in the housing.  So I looked for other 6ccfl inverters that may be slightly thinner.
 Here are 5 inverters that are designed for 6ccfl monitors.  From top to bottom: an iMac G5 inverter, aftermarket on ebay (4pin/2pin), aftermarket on ebay (2pin x 3), a 20" apple cinema display inverter, and the aftermarket inverter used above.  The only one that the case would close with (even with the dremel modification) was the cinema display inverter.  However, it still took a little force and unlike every other inverter pictured, this is not a straightforward inverter (there are actually 8 pins - more than the iMac).

 I had also thought about using LED lighting (which does not require an inverter) however after a brief test of constructing my own led rail, I was not happy with the results (uneven lighting).  Putting the iMac's LCD onto a commercially manufactured  20" LED backlit montitor would likely work very well.  However, they simply do not manufacture 20" LED backlit LCD's in the 16:10 (1600x1050) orientation, which would be required for this mod.

So, I am left with 2 options: Continue to search for a solution to the 20" backlighting problem or to complete the all in one mod using the already built 17' monitor assembly.  I do have another idea for the 20", so I am not giving up yet.  After using my previous 17" mod for sometime, I do have to concede that a 17" monitor seems awfully small these days and a 20" would be preferable.  Plus, I have located a 5 wire resistive 20" touchscreen which would be ideal for this mod.  If anyone has any ideas, tips, or suggestions, they would certainly be appreciated.