Rep: 1
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Excellent write up, Im having the same issue, screen sometimes comes on but most of the time it stays off. Once every 100 times after restarting does it come on.
I'll have to check this out, thank you!
I've been trying to track the issue down to the lvds connector but due to the lack or my knowledge and a visible gpu on this motherboard it's gotten to the point where I can't track the issue.
Is this a good question?
Rep: 7.6k
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I would have an issue tracking it too since Apple hasn't used LVDS on these models for three years now.
Is your problem intermittent PICTURE or intermittent BACKLIGHT? Caused by water, drop, power surge?
Don't even bother checking backlight fuse on newer retinas as it is always good.
You could start checking voltage on both sides of L8300. Then voltage on pin 1 of the LCD connector, which uses displayport, not LVDS. Do we have no backlight, no image, LCD not detected because of issue in DDC circuit, LCD detected but not powering on because that little POS U8300 they put right by the vent got water on it?
Next thing to do is measure and report back findings.
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Sorry for describing shi* without doing much research. I'm getting intermittent display, back light is ok.
Will report back tomorrow with the readings I'm getting. Thank you!
zzz,
I'm reading 5V on both sides of L8300, and 38V on pin 1 of lcd connector.
I have a boardview and schematic, but im new to reading schematics....viewing a few videos and doing some reading on how to read it.
5v when you have video on the screen or 5v when you have no video on the screen?
5V when there is No video on screen, it's been 4 days now that the screen hasn't turned on.
Also, when connected to a video-out adapter, the external display works.
Rep: 23
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Hi there , pls help me to locate L8300 so I can check voltage level also pls help me how to check if the lcd display driver chip is ok or not what voltage I should read and how also pin diagram for that chip. Can I check F7700 fuse status while stil soldered on board, pls help my backlight is not light up after I removed the display cable while still system on . Sorry pls help
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i cant get 5v lcdbklt_fet_drv_r or c7741 can you help me
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i have backlight problem i changed u7700 and q7700 no backlight
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