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Stephen Tadlock
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LCD compatibility iMac 17"

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Are the LCDs interchangeable from a G5, Core Duo, and Core 2 Duo 17" iMac? I am looking for a replacement for my grandfather's 17"1.83GHz Core Duo. It is displaying dozens of vertical lines and has a distorted almost inverted color scheme (almost dead LCD)

Edited by: oldturkey03 ( )

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mayer
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These things are very picky as to which LCDs they will use. The picture you put up is a G5 but the question says it is a Core 2 Duo. Look on the bottom of the stand for the correct one.

Next, there's a possibility that this old machine is one that has a screen recall on it. Go to Applications > Utilities > Grab application and take a picture of the whole screen. Now move that picture around using your mouse and determine it the lines are present in the picture or just on the screen.

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remacberlin
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The LCDs on iMac G5 and the early Intel iMacs do look exactly the same, even the electrical connectors are the same (LVDS is a standart after all) and the inverter boards are identical but they are NOT interchangeble!

One panel is labeled LM171W02 (TL)(B2) and the other LM171W02 (TT)(A1).

Unfortunately i can't remember which one is which. But i think a little google might help.

If you fit the G5 panel (i think it's the A1) into a CoreDuo or Core2Duo the machine will refuse to start.

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Mike Bates
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becuase of the EEID. swap EEPROMs and itll work fine. You have to remember Apple has always been up to their dirty old tricks since day 1 of the operation. (proprietary, closed system, etc..) kinda like IBM was.

usually, some, if not all, have EEPROMS that tell the video BIOS/GPU what the panel model/type is, the max resolution, etc. known as the EEID. there is a dedicated EEID bus. some machines use it, some do not. The purpose for a machine to use an EEID is if the motherboard is used in several different display configurations. If the EEID is not used, usually its becuase of the motherboard only working with 1 screen type or resolution.

Apple is the same way, but they DO use the EEID. But, against us. the EEID reads back LM171W02(TT) (for a g5 isight), the mac will boot. anything else, the mac will not.

This goes for most if not all of them. You can swap out the eeproms that contain the EEID, and it will work fine. the system will see a TT panel even though your using a TL. vice-versa.

you can use 3rd-party panels the same way, as long as the resolution matches, etc.

Edited by: Mike Bates ( )

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macchanger
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+1 for the "how to swap the eeprom" or how to rewrite/flash this thingy. Mike, thanks a lot for your extensive explenation. We would really appreciate if you could reveal the secret if it is, and if, how it is possible to make the one panel work on the other machine.

Regards,

/macchanger

Edited by: macchanger ( )

The EDID EEPROM is small TSSOP chip on the board of the lcd panel, it is usually not very far from the video cable connector. What Mike did (as far as i am aware) is swap the chip from 2 different TMDS panels in order to trick his G5 into using a non-standard but otherwise fully functional panel. That being said he swapped TMDS to TMDS, not TMDS (G5)to LVDS(Intel). TMDS to LVDS cannot be done without actively converting the signals. Unfortunately i have yet to see a converter that would fit in the limited space afforded in the iMac. But in the case of G5 to G5, that EEPROM can be swapped from board to board with success, it involves some pretty serious soldering though(its small, and overheating can destroy it). Using an i2c programmer it can actually be programmed in place. If i get some time i will dig out a couple panels and post the EDID dumps, so if someone wants to program it they wont have to bother dumping the original screen.

senordingdong,

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