MacTester57's HemiMac G4

Discussion in 'iMac Mods' started by MacTester57, Jul 21, 2013.

Tags:
  1. MacTester57

    MacTester57

    Joined:
    Dec 15, 2011
    Messages:
    886
    Mobo:
    Z68MX-UD2H-B3, DQ77KB, NUC DC53427HYE, NUC D54250WYKH
    CPU:
    i5-2500K, i3-3225, i7-3770S
    Graphics:
    HD 3000, HD 4000, HD 5000
    Classic Mac:
    iMac, Power Mac
    Mobile Phone:
    iOS
    Jul 21, 2013 at 3:24 PM #1
    MacTester57

    MacTester57

    Joined:
    Dec 15, 2011
    Messages:
    886
    Mobo:
    Z68MX-UD2H-B3, DQ77KB, NUC DC53427HYE, NUC D54250WYKH
    CPU:
    i5-2500K, i3-3225, i7-3770S
    Graphics:
    HD 3000, HD 4000, HD 5000
    Classic Mac:
    iMac, Power Mac
    Mobile Phone:
    iOS
    Hi Guys

    A while ago, I've read jberg44's (aka dremeljunkie) blog with its wiring diagrams (great, thanks): http://www.dremeljunkie.com

    Recently, I've read Ersterhernd's NUCiMac thread an this activated the "must have reflex": http://www.tonymacx86.com/imac-mods/102250-ersterhernds-nucimac-g4.html

    Here is my project: The HemiMac G4 :ugeek:

    Why this name?
    1. The iMac G4 has a "hemispherical" base
    2. A "hackintoshed" classic Mac is like a Hotrod for me - classic body with modern innards - and they mostly have a big V8 engine with "Hemi" combustion chamber: http://en.wikipedia.org/wiki/Hemi_engine

    So I bought the 1st iMac G4 17" / 1.25 GHz:
    [​IMG]

    Unfortunately it is not in best condition: It was a scool computer and has some willful damage like a screen with scratches in every corner. I was disappointed and auctioned an 2nd identical unit, which hopefully will be in better condition:
    [​IMG]

    Goals of this project:
    -outside as original as possible
    -optical drive
    -original speakers, connected with the original 2.5mm plug
    -internal PSU
    -silent (the original iMac is loud)
    -working LCD backlight dimming
    -original "breathing" sleep LED (I intend to use a PICAXE microcontroller)
    -USB 3.0

    First works on the 1st unit:

    The optical drive door did not close properly, so I've added M3 washers under the screw heads:
    [​IMG]

    The "Fleckenradierer" is ideal for cleaning dirty iMac housings: (use a bit water)
    [​IMG]

    The back side after cleaning:
    [​IMG]

    A first look to the innards and cleaning:
    [​IMG]

    This is a USB 2.0 model (iMac3.3) and the connectors are not the same shape as Ersterhernd's:
    [​IMG]

    As I said earlier, one of the goals is a working LCD CCFL dimming. To allow this, some investigations on the inverter connector were necessary:
    [​IMG]

    [​IMG]

    As you can see, I discovered, that the "dimming" signal is on the green (neck) wire: 0.7V = Min. brightness / 3.14 V = Max. brightness! The orange wire has always 3.3 V and I assume, that it is for the 3.3 V supply of the inverter's microcontroller. We will see...
    [​IMG]

    MacTester

    Edit: some pictures of the modding process for comparison.
    iMac G4 Hackintosh Gallery.jpg

    Edit: video summary
    [video=youtube_share;42giS6Dn9Ws]http://youtu.be/42giS6Dn9Ws[/video]
     
    Last edited: Dec 27, 2014
  2. ersterhernd

    ersterhernd

    Joined:
    Nov 25, 2010
    Messages:
    1,189
    Mobo:
    MSI Z77MA-G45
    CPU:
    i7-3770k @ 4.3 GHz
    Graphics:
    PowerColor 6870 mDP
    Mobile Phone:
    Android
    Jul 21, 2013 at 6:22 PM #2
    ersterhernd

    ersterhernd

    Joined:
    Nov 25, 2010
    Messages:
    1,189
    Mobo:
    MSI Z77MA-G45
    CPU:
    i7-3770k @ 4.3 GHz
    Graphics:
    PowerColor 6870 mDP
    Mobile Phone:
    Android
    Wow! Those are aggressive goals, Mactester! Like your Cube, this project will certainly end up fabulous. I'm very interested in reading your take in the LCD dimming, as to what's involved in the wiring.

    Good Luck!
     
  3. rick26

    rick26

    Joined:
    May 15, 2012
    Messages:
    388
    Mobo:
    Gigabyte GA-170X-UD3\ Define R5 Case\ GA-H61M-S1 Cooltek Coolcube Maxi
    CPU:
    Intel Core i7 6700K \ Intel Core i5 2500
    Graphics:
    Evga Geforce GTX970 FTW \ Sapphire Radeon HD6870
    Mac:
    MacBook Air, MacBook Pro
    Classic Mac:
    iMac, Power Mac
    Mobile Phone:
    iOS
    Jul 21, 2013 at 8:37 PM #3
    rick26

    rick26

    Joined:
    May 15, 2012
    Messages:
    388
    Mobo:
    Gigabyte GA-170X-UD3\ Define R5 Case\ GA-H61M-S1 Cooltek Coolcube Maxi
    CPU:
    Intel Core i7 6700K \ Intel Core i5 2500
    Graphics:
    Evga Geforce GTX970 FTW \ Sapphire Radeon HD6870
    Mac:
    MacBook Air, MacBook Pro
    Classic Mac:
    iMac, Power Mac
    Mobile Phone:
    iOS
    Cool Mactester!

    this will be a tough job but I think it wil be worth it!

    So far I can see on the pics the screen looks okay.

    Men now I want an iMac g4 to:O

    Have fun Mactester! This wil be great to follow!

    Rick,
     
  4. MacTester57

    MacTester57

    Joined:
    Dec 15, 2011
    Messages:
    886
    Mobo:
    Z68MX-UD2H-B3, DQ77KB, NUC DC53427HYE, NUC D54250WYKH
    CPU:
    i5-2500K, i3-3225, i7-3770S
    Graphics:
    HD 3000, HD 4000, HD 5000
    Classic Mac:
    iMac, Power Mac
    Mobile Phone:
    iOS
    Jul 21, 2013 at 9:37 PM #4
    MacTester57

    MacTester57

    Joined:
    Dec 15, 2011
    Messages:
    886
    Mobo:
    Z68MX-UD2H-B3, DQ77KB, NUC DC53427HYE, NUC D54250WYKH
    CPU:
    i5-2500K, i3-3225, i7-3770S
    Graphics:
    HD 3000, HD 4000, HD 5000
    Classic Mac:
    iMac, Power Mac
    Mobile Phone:
    iOS
    Thanks, guys!

    I know, that those goals are aggressive. After I've disassembled the base and did some measuring I have to say that it will be almost impossible to integrate a mini ITX board under the optical drive - it would fit, but there is only 15mm height available...
    [​IMG]

    If I want USB 3.0 and an optical drive, I will have to wait for the Haswell NUC or will have to use the GIGABYTE BRIX GB-XM12-3227 (which only has 2 USB 3.0 ports)

    MacTester
     
  5. MacTester57

    MacTester57

    Joined:
    Dec 15, 2011
    Messages:
    886
    Mobo:
    Z68MX-UD2H-B3, DQ77KB, NUC DC53427HYE, NUC D54250WYKH
    CPU:
    i5-2500K, i3-3225, i7-3770S
    Graphics:
    HD 3000, HD 4000, HD 5000
    Classic Mac:
    iMac, Power Mac
    Mobile Phone:
    iOS
    Jul 22, 2013 at 8:52 PM #5
    MacTester57

    MacTester57

    Joined:
    Dec 15, 2011
    Messages:
    886
    Mobo:
    Z68MX-UD2H-B3, DQ77KB, NUC DC53427HYE, NUC D54250WYKH
    CPU:
    i5-2500K, i3-3225, i7-3770S
    Graphics:
    HD 3000, HD 4000, HD 5000
    Classic Mac:
    iMac, Power Mac
    Mobile Phone:
    iOS
    Today, I've done several works:

    1. Installing the new WiFi:
    I've used this TYCO Laptop Wireless Mini PCI PCI-E Internal Antenna:
    http://www.ebay.com/itm/TYCO-Laptop...na-/260668842387?ssPageName=ADME:L:OC:CH:3160
    [​IMG]

    To allow the antenna replacement, the faraday cage had to be removed:
    [​IMG]

    This is the old antenna:
    [​IMG]

    [​IMG]

    And the new one. An A1181 BT antenna was also installed:
    [​IMG]

    [​IMG]

    2. The bad part of the story... :banghead:

    The backlight does not work properly. I think the inverter died...

    This is the test setup with a 22kOhm potentiometer for the brightness-regulation. As I said yesterday, the green neck-wire is for the dimming. It works, but not as it should - @ 0.6 V the CCFL begins to flicker - @ 0.64 V it stays on, but is dimmed (as it should at this voltage, see table) - If the voltage rises over 0.7 V, the CCFL shuts off and can only be activated, if the red On / Off wire is removed from the 5V supply and then reconnected. I've also tested the wiring according to dremeljunkies table - that does not work either... (the CCFL turns on for about 0.2s and then shuts off)
    [​IMG]

    I then disassembled the whole screen unit. The inverter looks OK
    [​IMG]

    [​IMG]

    [​IMG]

    ...nothing changed after reassembling. Only dimmed light works. :banghead: Any thoughts?

    MacTester
     
  6. kiwisincebirth

    kiwisincebirth

    Joined:
    May 27, 2012
    Messages:
    777
    Mobo:
    GA-Z68MX / DQ77KB
    CPU:
    i7-2600 / i7-3770S
    Graphics:
    GTX 650 Ti / HD4000
    Mac:
    MacBook Air, MacBook Pro, Mac mini
    Mobile Phone:
    iOS
    Jul 23, 2013 at 12:17 AM #6
    kiwisincebirth

    kiwisincebirth

    Joined:
    May 27, 2012
    Messages:
    777
    Mobo:
    GA-Z68MX / DQ77KB
    CPU:
    i7-2600 / i7-3770S
    Graphics:
    GTX 650 Ti / HD4000
    Mac:
    MacBook Air, MacBook Pro, Mac mini
    Mobile Phone:
    iOS
    Hi Mac Tester, great build look forward to your progress.

    Re your current problem, I would go through normal troubleshooting steps. I would attempt to get back as much as possible to factory configuration to get a working backlight. Basically to find out if the inverter is actually dead.

    The assumption you have been working to ( I think) is that the brightness of the backlight is controlled by a DC voltage. It is possible that it is a Modulated signal (like pwm fan control), or microprocessor control line, and a multimeter is just taking an average (guess). You need an oscilloscope to get to the bottom of this.

    I remember mini hacks investigation of G4 CuBE power switch the extra signal to control the led, he couldn't resolve a simple DC control mechanism, so couldn't utilize the feature. My guess this was a micro controller signal. It is possible this is a similar situation.

    Question: does the inverter have any chips with identify able markings, that could lead to a data sheet, which might identify the control mechanism?

    Last thought. You have a second iMac with a working inverter, worst case you have a spare part, if you can't get the first one to work.

    Kiwi
     
  7. MacTester57

    MacTester57

    Joined:
    Dec 15, 2011
    Messages:
    886
    Mobo:
    Z68MX-UD2H-B3, DQ77KB, NUC DC53427HYE, NUC D54250WYKH
    CPU:
    i5-2500K, i3-3225, i7-3770S
    Graphics:
    HD 3000, HD 4000, HD 5000
    Classic Mac:
    iMac, Power Mac
    Mobile Phone:
    iOS
    Jul 23, 2013 at 6:19 AM #7
    MacTester57

    MacTester57

    Joined:
    Dec 15, 2011
    Messages:
    886
    Mobo:
    Z68MX-UD2H-B3, DQ77KB, NUC DC53427HYE, NUC D54250WYKH
    CPU:
    i5-2500K, i3-3225, i7-3770S
    Graphics:
    HD 3000, HD 4000, HD 5000
    Classic Mac:
    iMac, Power Mac
    Mobile Phone:
    iOS
    Hi Kiwi

    Thanks for reply.

    Yes, I assume that it is a PWM signal. I saw on the internet, that most of the inverters work with PWM or analogue regulated reference voltage. It is very strange, that it does not work either, if I wire it up like dremeljunkie and Ersterhernd did...

    I could not find a valid chip identification on the photo... Maybe you can?

    The 2nd iMac did not yet arrive... The other possibility is to pull the CCFL out and to replace it with something like that: http://www.ebay.ch/itm/Ruban-bandea...poules&var=&hash=item27ca21998a#ht_914wt_1413

    What do you think?

    MacTester
     
  8. MacTester57

    MacTester57

    Joined:
    Dec 15, 2011
    Messages:
    886
    Mobo:
    Z68MX-UD2H-B3, DQ77KB, NUC DC53427HYE, NUC D54250WYKH
    CPU:
    i5-2500K, i3-3225, i7-3770S
    Graphics:
    HD 3000, HD 4000, HD 5000
    Classic Mac:
    iMac, Power Mac
    Mobile Phone:
    iOS
    Jul 23, 2013 at 7:52 AM #8
    MacTester57

    MacTester57

    Joined:
    Dec 15, 2011
    Messages:
    886
    Mobo:
    Z68MX-UD2H-B3, DQ77KB, NUC DC53427HYE, NUC D54250WYKH
    CPU:
    i5-2500K, i3-3225, i7-3770S
    Graphics:
    HD 3000, HD 4000, HD 5000
    Classic Mac:
    iMac, Power Mac
    Mobile Phone:
    iOS
    It's working now - the dimming too!!! :D :D :) :)

    Details will follow. :beachball:

    Here is a short youtube video:
    [video=youtube;lIUTtO1-hRU]http://www.youtube.com/watch?v=lIUTtO1-hRU[/video]

    MacTester
     
  9. ersterhernd

    ersterhernd

    Joined:
    Nov 25, 2010
    Messages:
    1,189
    Mobo:
    MSI Z77MA-G45
    CPU:
    i7-3770k @ 4.3 GHz
    Graphics:
    PowerColor 6870 mDP
    Mobile Phone:
    Android
    Jul 23, 2013 at 10:15 AM #9
    ersterhernd

    ersterhernd

    Joined:
    Nov 25, 2010
    Messages:
    1,189
    Mobo:
    MSI Z77MA-G45
    CPU:
    i7-3770k @ 4.3 GHz
    Graphics:
    PowerColor 6870 mDP
    Mobile Phone:
    Android
    :clap:


    Way to go, MacTester!



    Ersterhernd
     
  10. rick26

    rick26

    Joined:
    May 15, 2012
    Messages:
    388
    Mobo:
    Gigabyte GA-170X-UD3\ Define R5 Case\ GA-H61M-S1 Cooltek Coolcube Maxi
    CPU:
    Intel Core i7 6700K \ Intel Core i5 2500
    Graphics:
    Evga Geforce GTX970 FTW \ Sapphire Radeon HD6870
    Mac:
    MacBook Air, MacBook Pro
    Classic Mac:
    iMac, Power Mac
    Mobile Phone:
    iOS
    Jul 23, 2013 at 11:44 AM #10
    rick26

    rick26

    Joined:
    May 15, 2012
    Messages:
    388
    Mobo:
    Gigabyte GA-170X-UD3\ Define R5 Case\ GA-H61M-S1 Cooltek Coolcube Maxi
    CPU:
    Intel Core i7 6700K \ Intel Core i5 2500
    Graphics:
    Evga Geforce GTX970 FTW \ Sapphire Radeon HD6870
    Mac:
    MacBook Air, MacBook Pro
    Classic Mac:
    iMac, Power Mac
    Mobile Phone:
    iOS
    Looks great Mactester good job!

    Rick,
     

Share This Page