iMac G5 LCD HACK

Here is a description of my iMac hack. I’f you have questions I’ll give my best to give you a reply. Check out my donation page. Support is highly appriciated, both directions.

 

It all started with this:

..a broken G5 iMac with burned PSU, I’m guessing from thunder strike
Sparky sparky ^^,

Project 1. iMac PSU replacement – G5 not Intel

After some digging to locate the atx pinout of G5 i managed to connect a standard pc atx power supply.

 

Standard ATX pinout:

For full pinout and more details about ATX powersuplies, visit my source:
http://www.smpspowersupply.com/connectors-pinouts.html

http://www.smpspowersupply.com

 

 

HOW TO USE standard PC ATX power supply with iMAC G5

 


Note the two pin that’ve changed and the additional 24 Volts on the iMac.

 

Here is a guide if you want more specific details:
instructables-Fixing iMac-Power-Supply/

     – This is how it looked when it was finished.

I realized that the G5 was not quick enough for running fullscreen Youtube videos (flash was laging….) so instead of throwing it from a bridge or run it over with the car (recyling).
I then decided to put a laptop inside the casing and just patch it up with the LVDS signals on the LCD panel.

With that said, the quest for my LCD panel datasheet had begun

LCD PANEL

After hours of googling I finally found the datasheet for my lcd-panel.
20 inch LCD IDTech M201z2
I noticed that I have the “unusual” lcd backpanel from IDTech.

Since I had the very rare LCD-backpanel, the datasheet was of course extremly hard to find, but finally I got it!
And here it is!  Link:elecfans.com-M201Z2
Today I’m the only online open and uncensored source of this document.

Here is the datasheet for the most common screen used with the iMac’s Philips LM201W01-SLA1
LM201W01-SLA1

If you appriciate these datasheets, click Donate  [paypal-donation]

It’s not about the amount, just to show your appreciation.

Anything from 0.1$ is accepted

(My webspace isn’t free… don’t let KARMA bite your ass!)

;-)

It seems that my IDTECH LCD-panel do not have LVDS signals!?
Instead it was equiped by a TI…. TFP403PZP-(Datasheet) A TMDS to LVDS controller!

This mean that the IDTECH LCD-panel can be connected directly to a dvi-source
i.e a DVI-D graphic card without any external controller board. Thus I decided to use it as a standalone Screen from a DVI source insted of putting a laptop inside the iMac-case.

Repetition part

I repeate this part since many many many people ask about it:

1 – IDTECH LCD display can be directly connected to DVI sources.

2 – THE LG/PHILIPS LCD display recuires a external LVDS to TMDS converter.

3 – LVDS is the +/-3volt low level and TMDS is the high level that you’ll find in DVI/HDMI ports etc. probably like +-15volt or something.
(LVDS = low level signals. TMDS = high levels. Its like comparing UART/TTL with RS232 or comparing a 9Volt battery with the Wall AC plug).

LG PHILIPS LCD PANEL – READ HERE
IF you have the LG PHILIPS LCD display, then you’ll probably need to find either a LVDS/TMDS converter OR find a trashed old LCD screen.
-Take it appart.
-Remove the controller and the powersupply.
-Measure the supply voltage for the controller board-
-Then you’ll need to locate the LCD panel pinout on the trashed OLD TFT/LCD.
-These have to be crossmatched with the LG/PHILIPS datasheet – above.
-Re-use the controller board in your iMac.

The controller board and power supply from a trached screen could look like this:
  

I’m sorry to write with capitals and bold text, I just need to clarify these parts since I receive allot of questions about it.

MY LCD BACKPANEL HACK – USING THE ID3tech SCREEN – NOT LG/PHILIPS

If you have the LG/PHILIPS LCD panel, read above ^ thank you…

Here is a Block drawing of my hack.

1. On the Left, my power supply (20volt DC 6.5Amp),

2. 5volt regulator and 555 momentary switch circuit.

3. 12 volts regulator for the LCD-panel and White LED

4. Inverter (apple).

 

1. Power Supply

Since my original power suply was burned I had to construct a new one.  Its a old universal laptop power supply which follows the spec 20 VDC 6.5Amp and has a buildt in cooling fan. I’m not going into details about it. Either you can use the original iMac supply, see the pinouts above. The 19-24 volt connects with the inverter.

2. My 555 IC momentary switch or flip flop

On the Left is the transisotr for controling the Relay. I’ve put a 12amps cmos, but this gave back currents and burned my 555 ic.

Instead I put a relay and across the relay a diode to protect against induktive transients (or whatever its called in english); cathode on the Diode should be in the direction to the transistor. Anode to ground.

For the 5 volt regulator I’ve used a LM7805 regulator with two capacitors. Its a simple, cheap 5 volt regulators.

Datasheet here: http://www.sparkfun.com/datasheets/Components/LM7805.pdf

The relay toggles the incoming 20volt for the 12 volt regulator and the backlight inverter.

Original idea for this circuit is from www.todbot.com/blog  Original schematic from http://www.bowdenshobbycircuits.info/

 

3. 12 Volt regulator

Drives the LCD backpanel. The Id3tech pulls about 0.5 Amps@12volt

The backlight pulls about 3Amps@20 volt

the voltage regulator was attached with silicon paste to the back of the iMac casing, for cooling. It’s a LM7812 regulator, similar to theLM7805  supplying the 555 circuit above, but with 12 volt output instead of 5volt.

I also added a white LED in series with a 6.4kOhm resistor to the 12 Volt output from the LM7812.

The LM78xx are very easy to use:

Datasheet here: http://www.sparkfun.com/datasheets/Components/LM7805.pdf

 

 

4. APPLE iMAC Inverter

Here is the pinout for the imac G5 backlight inverter table.

Carefull with the highvoltage outputs!! Sparky sparky!

Since I didnt had a scope at the time, I could not verify the brightness pin, but I asume its a PWM signal. If you have more details about this, please let me know and I’ll put it here. “Assumption is the mother of all fuckups”.

 

I had problem with flickering backlight, it was fixed by pulling extra ground cable between the inverter and powersupply.

 

Here is a look inside the iMac.

[youtube]http://www.youtube.com/watch?v=bWSYF2I_LeM[/youtube]

 

 

Unfortunate I had to make space at home, so the iMac and allot of other things have been trashed. thus this project has halted.

If anyone need help though, dont hesitate to ask or e-mail. Or leave me a commenct down below.

[youtube]http://www.youtube.com/watch?v=-1Rz4ve8AV4[/youtube]

 

LINKS.

many sites have appeared from when I first put the soldering iron in my screen,

here is a few, well worth the visit;

http://www.dremeljunkie.com/2011_08_01_archive.html

 

 

Disclaimer:

I bought this screen secondhand thus I’m not aware of any agreements with APPLE corp. of not beeing allowed to alter their hardware.

I dont take responsibility if you are doing something wrong and get electrocuted or burn your lcd-panel. Its up to you to follow up and confirm the information given.

 

With that said, go and do some hacking!

 

[paypal-donation purpose="iMac_Hack" reference="donation_iMac"]

Thanks for reading.