Macbook Pro LCD Screen Works Sometimes / On/Off

Question

Macbook Pro LCD Screen Works Sometimes / On/Off

For several months my (late 2007, 15 in) macbook pro screen was not working at all. I took it to apple at one point and they said I would need to replace my screen which would cost at least $400 or $600 I can't remember how much. I just knew it was too much.

Then recently I found out that my model had the NVIDIA GeForce 8600M GT graphics processor and Apple found out those had a problem in a number of those computers so they are supporting it by replacing the mother board.

So... I got my new mother board recently but the screen was STILL not coming on at all after the repair. One conclusion was obvious I needed a new screen or just use the computer as a desktop with an external monitor which is what I've been doing.

So now, here's the rub:

My SCREEN MAGICALLY HAS COME BACK ON just last night and this morning... it was working and then Poof it went off again.... now again it's magically come back on.

When working there isn't any streaks or anything that appears damaged on the screen at all. My guess is that there is some cable or some connector point that is loose and somehow like a short makes it go on and off.

Now, part of what has been going on since yesterday is that I just replaced my hard drive so I've had the cover of the computer off... somehow I did something to they keyboard so I'm having to use an USB keyboard right now (might have to replace that too). So... somehow my taking off the cover and putting it back on a few times must have touched something that is making it work again.

What could it be? Any ideas? I'd be grateful for any advice that would keep me from having to try buying a new screen as I understand I have to replace the whole piece.

Thanks,
phil

macbook pro, 15, 2.2 gig, 500gb HD, Mac OS X (10.6.4)

Posted on Sep 26, 2010 3:25 PM

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Answer 1

S.U.

Level 6

9,601 points

Sep 26, 2010 7:20 PM in response to macbookproyes

There should be some flex cables that plug the display into the logic board. Check to see that these are well seated--it sounds like they are loose and making an intermittent connection. That is the most likely problem. Look for display replacement instructions to see where they are and what they look like.

There is also a flex cable to the keyboard that I believe you need to unplug in order to replace the hard drive. It could be that this cable was not properly reconnected upon reassembly.

Good luck!

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Answer 2

Sep 29, 2010 1:22 AM in response to S.U.

I figured out what was 'wrong' with the keyboard. It was having a problem because I hadn't tightened all the screws yet because I was also about install a new optical drive.

Anyway, I will check the cable you mentioned for the screen. I will say that the screen was periodically going out and stopped working altogether for a couple months. That was when I called a repair tech at one point who told me it could be the NVIDIA GeForce 8600M GT graphics processor went out which Apple is supporting.

Anyway, an Apple certified tech replaced the mother board so I could at least use the computer with the external monitor.

However, the Macbook Pro screen as I mentioned came back on recently but after not working at all. A little while ago after using it for a while (perhaps it was kind of hot) the screen went out again and here I am having to plug back into my external monitor.

I'll look for that cable connector and if I can't fix the problem then I'll take it into Apple to check it out.

I'm hoping I don't have to actually replace the screen.

thanks for the suggestion,

Phil

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Answer 3

Sep 29, 2010 5:10 AM in response to macbookproyes

I took a pic of my screen with vertical streaks of color. I'm curious if anyone thinks it could be the connector points of the display cable or inverter cable.

Here's a picture of my screen.

[IMG] http://globaleventsnetwork.org/screen-vertical.jpg[/IMG]

Hopefully it's not the LCD itself. I'm wondering if there's hope it could be a cable before I start messing around with it.

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Answer 4

S.U.

Level 6

9,601 points

Sep 29, 2010 1:19 PM in response to macbookproyes

You could probably get whoever replaced the logic board to check the cable connections since they are the ones who plugged them in when the board was replaced. They could also check to see if there is some problem with the cable which is keeping it from full seating. Or you could--look for something like a foreign object in the socket, bent pins, anything mechanical that could be causing a problem. You may need a good light and magnifier. The fact that it works sometimes points toward an intermittent connection of some sort. It could even be in the flex cable itself--maybe a broken trace that sometimes makes contact and sometimes does not. If you can't find the break, possibly the tech can.

Good luck!

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Answer 5

Sep 29, 2010 1:58 PM in response to S.U.

Yes I'm using an external monitor now. FYI, I was having this problem before this certified mac tech replaced the motherboard. At one point the video screen wasn't working for a couple months but I got an external monitor and was using that until the video stopped working on the external monitor. That's when I got the diagnosis of the common NVIDA chip problem and then they replaced the motherboard.

So, what I'm saying that if it is a 'connection problem', it existed BEFORE I got the motherboard replaced.

Question: When the motherboard is replaced the tech would have had to unplug and replug back in the video cables to the motherboard right? Further, if that is the case and I'm basically having the same problem now as before... then... wouldn't it stand to reason that it probably wouldn't be the actual 'plug in' points but if it is something to do with the cable it would most likely be "the Flex Cable Trace is broken somewhere or something like that right?

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Answer 6

S.U.

Level 6

9,601 points

Sep 29, 2010 2:14 PM in response to macbookproyes

Understood--that's why I wondered if there might be some flaw in the cable itself or the connector which was preventing a good contact when plugged in. It may be worth trying to find a replacement cable, as Apple would want to replace the display and cables as a unit. I don't know if ifixit or powerbook medic would have separate cables, but it might be something to look into. If the cable itself is damaged, it would likely be where it flexes when you open and close the display.

Since the cable did work at some point and does not now, and did work intermittently for a while, damaged traces in the cable itself is the most likely scenario.

Good luck!

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Answer 7

Sep 30, 2010 6:02 PM in response to S.U.

I placed an ad on Craigslist that I was looking for a new LCD for $100 just in case I do need one. I got a call from a guy today who does some repair work. He hasn't specifically worked on macs that much but he claims that the LCD actual parts behind the scenes are the same in a macbook pro as potentially what came out of an Acer 15.4 laptop.

Is this potentially so that Apple uses the same manufacturers that other PC laptops do for things parts like an LCD and therefore it might be compatible?

I am somewhat doubtful that is the case, but it's hard to say. He told me that he did a search that showed compatible LCDs and his model # came up.

He's willing to take the cover off & first see if in fact it could be something do with with a tracer wire or something pinched in the cable before trying to replace the LCD. Additionally, he's willing to only get paid if he gets my LCD working again, whether fixing the cable or replacing the LCD at a very reasonable price.

Any thoughts on this?

thanks,
Phil

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Answer 8

S.U.

Level 6

9,601 points

Sep 30, 2010 7:30 PM in response to macbookproyes

That's a very interesting offer. There are a finite number of LCD manufacturers, and it could be there are models that can go in different computers. The construction of the display and the cables would be different for different computers. It would depend on whether the LCD is specifically configured for Apple or if Apple uses an "off the shelf" LCD and then configures the housing and cables.

Generally, in manufacturing, you try to use as many off the shelf parts as you possibly can. For example, you would use standard screws and fasteners unless you had a special need for a non-standard one. If there is already a LCD on the market that meets your specs and your needs, then it would make sense to use it rather than to have something special made.

I still suspect that the problem will turn out to be a connection one rather than one with the LCD itself. There have been cases where the flex cable developed damage from opening and closing the computer. This would be the first thing to check. A break in the trace or traces in a flex cable would allow for intermittent working of the LCD, depending on whether the broken traces were touching or not.

If the price sounds reasonable, then it sounds like you don't have much to lose by letting the guy have a shot at it. I wonder if he would let you watch while he works--it might be very illuminating.

Good luck!

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Answer 9

Oct 1, 2010 12:05 AM in response to S.U.

Well, I got back from being with this computer repair guy. I worked with him in taking off the back and watched while he took off the screen and we looked at the cable wires. There's no way to tell if there was a connector with a bad trace wire. The connector points that we saw all seemed fine.

The only connector areas or cables that could have had a problem are where the LVDS cable goes from inside the screen down into the enclosed cable area before it comes on to into the computer as well.

There's a small section of cable where the screen bends and it's all rolled together where maybe a tracer wire could have broken from opening-closing of the screen.

I'm starting to doubt the idea of it being a problem with the cable or connector points at all. I think it's time I surrender to the idea that it's just the LCD and I'll have the bite the bullet and just buy one and swap it out.

I've seen a guy on Ebay selling them for $122 which seems very reasonable actually and this local repair guy is willing to install it for like $60.

Thanks for all the advice,

Phil

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Answer 10

Oct 1, 2010 12:07 AM in response to macbookproyes

BTW, I forgot to mention that the two LCDs he had no real chance of working at all. I thought it was a shot in the dark. I'm just going to find a real apple LCD for a macbook pro 15 and that is that I guess.

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Answer 11

Oct 1, 2010 4:31 AM in response to macbookproyes

BTW, here's a listing I've found on Ebay for a replacement LCD for $122:

http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&item=200377572235&ssPageName=STRK: MEWAX:IT

Does this seem like a good and real Apple LCD that I could trust will work?

Thanks,

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Answer 12

S.U.

Level 6

9,601 points

Oct 1, 2010 1:46 PM in response to macbookproyes

It looks like it is for a Model A1211. Look at the printing on the bottom of your Mac to see that you have a Model 1211. If you have a different model Mac, it may or may not work. Usually you can find compatible LCD's at PowerBook Medic and ifixit, which will often give enough information to know what will and won't work. Apple changed displays every so often, and ones for one model usually won't work in a different model.

You can also email the seller and ask if you have a different model MBP. If you do have the A1211, then it should work. It looks like this guy came up with a lot of these.

Notice that it seems to be the LCD only without the housing. Be sure to ask about the cables, as you may as well get new ones if you can. It looks like there is something at the lower right corner, but I can't tell what it is. It may just be what the cable plugs into.

You might hunt for cables first, and if you find some, get them in first and try your LCD. It's still possible there is damage in the part you can't see. It would be a royal pain to replace the LCD, only to find that it was a bad cable all along.

There should be two cables, an Inverter cable, which has to do with backlight control and brightness, and a LVDS cable, which carries the video signal. Since the problem seems to be a black screen, I would hazard a guess that it is the inverter cable that is not working properly.

Good luck!

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Answer 13

Oct 1, 2010 6:29 PM in response to macbookproyes

I took two screen shots that someone on another forum suggested. The first screen shot was with the external monitor unplugged. The 2nd screen shot was after I plugged the screen back in. One interesting thing that I don't understand is that I had changed my screen background from the default purple starry sky background to a background with green fuzzy fruit looking things. Anyway, for some reason the 1st screen shot w/o the external shows the previous background that I had already changed. Then I plugged the monitor back in and took the 2nd screen shot which shows the green background that I've been using.

Here's the 1st screen shot without the external showing the background that I had changed from:

http://globaleventsnetwork.org/Screen-shot-w-o-external.png

Here's the 2nd screen showing the current background that I've been using:

http://globaleventsnetwork.org/Screen-shot-with-monitor.png

Any thoughts?

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Answer 14

Oct 2, 2010 1:31 AM in response to macbookproyes

I'm thinking it doesn't have anything to do with the Inverter or Inverter Cable as the screen isn't black it still shows colors mostly blueish, purple * grey but it's not black. Its my understanding that the Inverter has to do with brightness and in using the brightness / darkness buttons it does show it getting brighter or darker.

This is what the screen looks like:

http://www.globaleventsnetwork.org/screen-vertical2.JPG

You mentioned confirming Model A1211 you meant for the screen itself right? You also mentioned "bottom of your Mac "... did you mean on the bottom of the inside of the screen?

I'll see about getting a replacement LVDS cable too. I did see one LVDS cable I think listed somewhere for sale. If it's not too much perhaps I'll get one also.

Thanks,

Phil

Message was edited by: macbookproyes

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Answer 15

S.U.

Level 6

9,601 points

Oct 2, 2010 9:01 AM in response to macbookproyes

Looking again at the screen shot, I now think the faulty cable--if it is a cable--would be the LVDS cable.

The model number is on the bottom of your Mac near the hinge. There is a bunch of writing and symbols, and in very tiny writing on the top line will be the model number.

Looking at Mactracker, I see that Model Number A1211 is for the MBP 15 inch core 2 duo, or MacBookPro2,2 from October 2006 to June 2007.

No idea about the different backgrounds on the external.

Good luck!

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