zaterdag 14 december 2013

Imac g5 mod feat, - intel DH61AG

I always loved the design and feel of the ‘ retro’  imac g5, but the original g5 machines are real loud (noisy), and there performance is not up to the demands of modern day use.

So i took it on me to create a ‘ hack mack’ of an old defective g5, using some original parts. First stripping the old imac, then building it up.


The ' Hack Mac'  in action.

New parts :

  • intel DH61AG motherboard ( new thin mini itx form factor by intel) feat. I5 cpu (upgadeble to i7), 8 gb ram, integrated video,
  • intel ssd 60 gb
  • sata hd 300 gb 2.5
  • universal inverter
  • dell power brick



The original parts i managed to salvage and re-use in the new layout of the ‘ hackintosh’  :

  • original screen (using a modded origal tdms cable to connect directly to a dvi connector of a old videocard.)
  • small piece of the original logic board (ports, power button etc.)
  • original speakers
  • original imac superdrive (using a atapi to usb adapter)
  • original wifi/ bluetooth wiring. (in combination with an old g5 antenna)


The screen mod :

First problem i had to tackle was the screen. The advantage of using the original screen is that there’s a tmd to lvds converter build in the display. This makes it possible to solder a dvi connector to the original imac cable. On the downside - it’s a real precise and time consuming job to do…

First step was figuring out the pinout.
I used a lot of different sources to figure this out. A good source is www.dremeljunkie.com 

My test setup.
the backlight is turned on automatically.

I redid it, this time a bit 'cleaner'
The result was rewarding.
connector schematic 






After some testing-  all was working fine. I repeated the proces, only this time a bit ‘ cleaner’  i used hot glue to isolate all the connections, the result – a strong tdms to dvi cable. J

Next -> the case (layout of the parts.)
Lay-out of all the new parts.
The imac g5 case doesn’t have a lot of room for parts, and ventilation is always a concern.
I had to figure out were to put all of the components. Keeping in mind that upgrading (for example the hd’s) was possible and easy to do. The space in the middle of the case is unusable because of the expansion of the stand. So the motherboard has to be on the right side of the case. (looking from behind the mac) I placed the inverter on top, because of the vent that’s positioned  in the top of the casing (see back imac) the only room for hd’s was on the left side of the case.
So after figuring this stuff out i just went with it, handling one problem after another.

mounting the lcd cable.

It was not possible to mount the cable in the old imac-way. I had to make a little hole in the backplate, to put the cable through, next step was mounting the dvi connector. I used an old logicboard bracket.

atx bracket.

To Mount the intel dh61ag motherboard, i created a new atx backplate - using an old atx frame i had laying around.

















Drilling a hole in the right spot made it possible to use the old logicboard mounts and the atx conversion is a fact.


mounting the universal inverter

I had to remove a couple of old logicboard mounts to make room for the inverter. The top of the case was the most logical place to put the inverter. (heat dissipation) Again i made use of the old logicboard mounts. The original backlight cables were too short, so i made an extention cable for the backlight cable.





mounting the cpu – cooler

To get the cooler in place i had to drill a hole in the backplate. I made a new stand using 2 old atx motherboard-stands.














harddisk bracket.
My plan was to fit two hd’s on the left side of the case (next to the original imac ports).
Using the corner of a old monitor bracket i bent a new hd bracket. I had to drill a couple of holes and fitted a new ssd and a normal 2.5 inch sata hd. See pic. Mounted the bracket using a old logicboard mount.






Original ports an powerswitch conversion.

First step of the atx conversion was salviging a part of the old logicboard. I made new connections, using the ide-connector of an old dvd-player. I sawed of the connector the dvd board, and glued it on the old logic board (see pic.) To connect the old logic board-ports to the new motherboard i used old usb flat cables. This worked great.

ide-connector dvd-player
glued on the old logic board.

hot glue (isolate the connections) 
The result

Next step was soldering a old atx powercable to the existing powerswitch. After that was done, i soldered seperate wires to the usb solder points on the logic board. Now it is possible to connect and disconnect the logicboard (usb) ports – if needed.

power light mod



Superdrive atapi to usb conversion.

On ebay i bought a usb to atapi adapter, this made it possible to re-use the old slotloaded superdrive that came with the imac. Giving it the original feel.

I had to cut a corner of the metal cover of the superdrive to make the atapi adapter fit.



Cooling mod, (for propper cooling).

Cooling was a problem, i discovered after some testing that the heat was building up, so i made a square hole in the back of the imac cover. Is used a plexiglass cutout (scrapped from an old monitor) to cover the hole. Using small spacers i created some room to ‘ breathe’ . The result - a nice looking backplate with extra cooling vents.



I mounted a second cooling fan were the original fan was located, but this fan was verry loud, so i disconnected this fan, and left it in place just to be on the safe side. (turned out to be redundant)

After some testing the motherboard was a lot cooler but still there was a heat build up at the bios chip. So i took an old pentium 3 cooler and drilled a hole in the plexiglass plate. Next - i mounted the cooler in the hole.

The result a nice lookin and really sillent working fan, now the temps are much better.






Connecting the speaker cable, and all the other components  to the new motherboard.

The original connectors where to long - so i had to mod them using little isolated jumpers. See picture. This way the connections are nice and flat.

For the speakercable i made a conversion adapter using a old dvd ide-connector soldered to a speaker connector.

Mounting extra wifi antenna and using old bluetooth antenna.( removed from old g5 logic board)

I discovered that the wifi signal with one connector hooked up to the wificard was weak. So i took a old powermac g5 wifi connector and connected that to the second wifi connector. Then i took the existing bluetooth antenna and hooked that up to the ppc g5 wifi antenneport. The result – a strong wifi signal.

Conclusion

Converting an old imac is not easy to do, but it's certainly not impossible, and i’m happy with the end result.
The hack imac still got the imac feel, and the performance off the new motherboard is really snappy!!
I will probably upgrade the cpu in the future to intel I7.
Thanks for reading, and keep modding J

PK