iBook G3 Clamshell display replacement failure, a cautionary tale

mac27

Tinkerer
Apr 30, 2024
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I noticed a few weeks back that the display panel on one of my clamshells was beginning to succumb to vinegar syndrome. So after consulting with others more familiar with these than myself, I ordered a new replacement panel from the 'bay, making extra certain to match the original panel exactly. They are both the Samsung LT121SU-123 panel.

IMG_1029.jpeg

New panel (top), original panel (bottom)

When I went to install the new panel, I found that the display cable connector on the new panel appeared to be flipped 180 degrees on the board relative to the new one. The connector has two tabs on each side at the ends, so that it's directional and can only be installed one way:

IMG_1035.jpeg


So I thought "no big deal" - I simply rotated the wires from the cable the other way, connected everything up, and got the new panel installed. Something minor probably changed with the way they manufactured the boards over the years and the connector changed orientation. It should be just fine, right?

Turned on the iBook, and ... no image, no signs of life on the panel.

So I reinstalled the original panel, and ... no image, no signs of life on the panel. (This was obviously working fine before, apart from the vinegar syndrome).

Whelp, a kind commenter on 68kMLA provided this diagram which shows what happened:

1764879193463.png


Flipping the connector to hook up the panel caused a direct short to the 3.3V line on the connector. So stuff got cooked.

So I now have two damaged panels (maybe?) and a damaged iBook motherboard. What a colossal fail.

Let this be a cautionary tale to anyone else attempting this repair. No idea what to do next - do I gamble on yet another panel of unknown compatibility? Now that I've learned that the model identifier is irrelevant and has no bearing on whether it will actually work.

I'd love to hear from anyone can explain - WTF? Why would Samsung make panels that are identical in every way (using the SAME identifier) but flip the connector, guaranteeing that you will fry your device immediately?

*sigh* If anyone has a replacement 366 MHz FireWire clamshell motherboard, I am in the market...
 

wottle

Active Tinkerer
Oct 30, 2021
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Could you clip the arms off the connector so you could insert it the proper way? Of course, that assumes all the pins are actually the same and its not a whole new pin layout... Obviously that only works if you can find a new logic board, and verify nothing in the LCD was also fried.
 

MeTheMac

New Tinkerer
Feb 20, 2025
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Mars
Huh. I guess this is what happened to my magically stopped working clamshell after I swapped the screens from an Indigo one...
 
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mac27

Tinkerer
Apr 30, 2024
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Virginia, USA
www.mac27.net
Could you clip the arms off the connector so you could insert it the proper way? Of course, that assumes all the pins are actually the same and its not a whole new pin layout... Obviously that only works if you can find a new logic board, and verify nothing in the LCD was also fried.

I've been going back and forth with the seller, and they suggested this. It makes me a bit nervous, as that also assumes there are also no OTHER differences between the panels (🤷🏼‍♂️) but unless anyone sees an issue with doing that, it's what I'll try next once I get a replacement motherboard.
 

wottle

Active Tinkerer
Oct 30, 2021
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Fort Mill, SC
I've been going back and forth with the seller, and they suggested this. It makes me a bit nervous, as that also assumes there are also no OTHER differences between the panels (🤷🏼‍♂️) but unless anyone sees an issue with doing that, it's what I'll try next once I get a replacement motherboard.
Might be worth trying to at least confirm that the ground pins are where the schema expects them to be. Would at least increase the confidence level a bit.
 
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MeTheMac

New Tinkerer
Feb 20, 2025
72
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8
Mars
i assume you mean that just the display stopped working? On mine everything else still works (drives, caps lock light, speaker/chime) but just the display is impacted.
Yeah so I did a motherboard swap from a 466 mhz onto a 366 mhz indigo case, worked fine with the 466 screen assembly (grey). Swapped out the screens and bam, no luck. I still hear it booting up and everything. Switched it back, nothing. Its been a while so now I have a fully working lime model
 
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