LCD display not working , external display works properly.

Device having issue: MacBook Pro 15" Core 2 Duo Model A1226

I have read plenty of related issues but none identical to the display issues I'm experiencing.

Background: I had a display issue prior but was fixed by Apple as a recall and was still under warranty. (3.5yrs ago)

Current issue:

Boot up displays on LCD (Apple log and animated circle), once the OS is loaded (login screen) the LCD goes black. Tried the flash light at an angle test, nothing shows, just black. Plugged in an external monitor/LCD, log into the OS and the laptop works perfectly.

Checked system preferences: Only the external monitor is listed and detected. Tried to re-detect monitors, only the external one is found.

Under system profiler:

Displays:

Display Connector:

Status: No Display Connected.

Light sensors seem to work as keyboard lights up

Tried the PRAM and NVRAM reset - No change.

Tried a fresh install of the OS to an external drive and got a strange result:

Both the LCD and external monitor works (almost like in mirror mode) but the mouse movement can only be seen on the external monitor.

I made the following assumption (Please feel free to correct):

1. Not a video card error since an external monitor works.

2. Not an LCD issue since it works on boot up

3. Not a software issue (OS) since a fresh install has the same results.

So now I"m looking to open the laptop and start changing parts. Could someone please give advice an what part to change out. Should I try the video cable, or the inverter?

Your help would be greatly appreciated!!

Answered! View the answer I have this problem too

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Luckily the culprit was the video cable.

See my comment below.

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3 Answers

Chosen Solution

Luckily the culprit was the video cable.

I had a relatives MBP who was having video issues as well. After swapping parts out I was able to determine the following:

My logic board was ok after swapping LCD's (the whole display unit + cables) (My MBP was fully functional). Replaced my original LCD and started the following process of elimination:

swapped inverter board - not the culprit

reinstalled original inverter board

swapped video cable - display working, my MBP fully functional

second MBP had the video problems.

Placed an order for a video cable

On my relatives MBP orginal LCD black. Added external monitor , same thing black.

Notice the keyboard caps lock did not light up or back light ambient lighting did not work.

Trackpad did not work.

Performed the following:

Swapped the top case w/ keyboard from my MBP to my relatives MBP.

Caps lock light work and ambient keyboard lighting worked. Trackpad worked.

Pressed on F2 and display turns on. (somehow when the original keyboard failed , display went dim)

Performed the following for processes of elimination:

Removed upper case cable from my MBP and swapped with the upper case cable of my relatives MBP. Reinstalled the original uppercase (with my uppercase cable) on my relatives MBP.

Found the problem on the first try:

My relatives orginal keyboard/trackpad uppercase worked.

Ordered an uppercase cable for my relatives MBP.

So after a couple of months of research online and one actual visit to one of the Apple stores for an NVIDIA check test.

I was able to fix two old but fully functional MBP's for less than $50.00

Thanks in Advance for everyones help, especially on this website (ifixit)

You gotta love the internet

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Most Helpful Answer

This does not sound like a hardware issue to me with the exception that it may be the hard drive. First try starting up in Safe Mode (by holding down the Shift key. Next, boot from your system installation disk? Next, disconnect your hard drive and boot from your system installation disk. Please let us know your results.

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Getting different results:

Safe mode the same, laptop boots up with LCD then displays to the external.

Using Tiger DVD:

With external monitor connected, Tiger boots up (initial display on LCD), after boot sequence it completed; displays on both internal and external monitors, output on both garbled.

With external monitor disconnected , Tiger boots up (initial display on LCD) does not complete the boot sequence and hangs.

Using Leopard DVD:

With external monitor connected, Leopard boots up (initial display on LCD), after boot up sequence completes both displays working, however only the mouse movement can be seen on the external monitor.

With external monitor disconnected. The system boots up (initial display on LCD) boot sequence does not complete and hang.

For curiosity: Used a Windows 7 DVD. results were similar to that when using the Leopard DVD.

Repeated same tests above with the hard drive remove; same results

Any ideas?

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I am actually having this exact same problem... any solutions yet?

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I'm actually following and waiting for another user on this site, I'm following his post; take a look here: Screen works during boot but goes black once loaded

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I would restore the firmware. You can do this my visiting Apple's support downloads on their website. Look up you're model and burn the restoration CD and follow the steps.

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Installed the latest firmware, no change. Do you know where to get older versions of firmware? Almost looks like I have to down rev the firmware.

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n3xxus will be eternally grateful.
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