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MacBook Pro Unibody - No Backlight - Logic Board Question
- Thread starter Dadioh
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I can't seem to PM you. Maybe you need a few posts before that is possible. PM me if possible.
So back in June I spilled about a half a glass of water on my keyboard on my macbook pro. I took it to apple, and they, of course said they can fix it with a price. Im a broke college student and can't afford this, so i just left it in my room. (No matter how many times i pressed the power button, it wouldn't turn on). Come August, I decided to just plug it in (to the charger) and press the power button to see if it turns on. When I plugged the charger into the laptop, it just booted up itself, without me pressing the power button, i was extatic. Everything worked fine, all the keys and the mouse. the only thing that didn't work still was the power button, so i knew i had to keep it charged 24/7 in order for it to be used. But alas, while i was in class, i guess i forgot to plug it in, and it died, every since then (about two - three weeks ago) it hasn't turned back on....so i see/heard that you can short a specific place in the back of the macbook in order to start it, and also, you can press the right keys to also start it....is this true...what should I do? I know my computer works and everything, because it was working perfectly for about a month...
Where are the 3 and 9 pins, and how do you exactly "Short" something?
Where are the 3 and 9 pins, and how do you exactly "Short" something?
Thanks for the schematics Dadioh, I replaced the fuse and it fixed my backlight. haha it's funny cause now I have another problem, when I turn it on it shows the gray screen and the apple screen shows up and everything is lit up but after the gray screen it turns blank. I plugged it in to an external display and everything shows up fine. I have got a 15.4 2.53ghz with a Nvidia 9400. What else could I check?
@Dadioh,
Right I managed to get another pic of the front of the motherboard couldn't take one of the back as when I was taking the board out I had a problem with one of the screws, all the others came out except for one which wanted to play silly buggers, so now I have one screw that is threaded, any ideas of the best way of getting this one out ?
Cheers
Liam.
Attachments
@Dadioh,
Right I managed to get another pic of the front of the motherboard couldn't take one of the back as when I was taking the board out I had a problem with one of the screws, all the others came out except for one which wanted to play silly buggers, so now I have one screw that is threaded, any ideas of the best way of getting this one out ?
Cheers
Liam.
I assume that you mean that the Philips head is rounded out so that the screwdriver just spins around in the resulting crater? If so there are a couple of tricks I have used. If you have a "Good" quality Torx set (something like Wiha, not the $1.99 sets from China) then you "may" be able to use a torx to grab enough of the crater edges to back it out. A cheap Torx will probably just make a bigger crater
The other technique I have used is not for the feint of heart. Cover the entire board with a protective screen (I use an ESD bag) with a cutout for just the screw head. Tape it down around the edges so no metal filings can get to the board (VERY important). I then use a fine cutting wheel on my Dremel tool to cut a notch straight across the head of the screw. You then have a slot to use with an appropriately sized flat head (slot head) screw driver. Use this technique with extreme caution however. Metal filings = very bad for electronic circuits.
Third option. I don't have one in these tiny sizes but I heard there are "easy out" heads that can bite into the screw and back it out. I have larger easy outs for large bolts (like in car repair). They are basically a tapered reverse screw that bite into the crater and screw themselves in. Eventually they bind and will back the screw out.
In my experience this type of issue is caused by using screwdrivers that are low quality and do not have hard enough tips. The Wiha brand ones that I use have extremely good quality tips. I have never regretted paying the extra $$$ for them. Example
http://www.ebay.ca/itm/Wiha-4-Piece...ultDomain_0&hash=item2eb727afd9#ht_500wt_1156
Good luck.
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Have you tried an SMC reset and a PRAM reset?
SMC reset
http://support.apple.com/kb/ht3964
PRAM reset
http://support.apple.com/kb/ht1379
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From another thread of mine...
https://forums.macrumors.com/posts/12269545/
[Have you tried an SMC reset and a PRAM reset?
SMC reset
http://support.apple.com/kb/ht3964
PRAM reset
http://support.apple.com/kb/ht1379
Yes I have tried both. no success. If it was anything related to my board you would think that the video out wouldn't work when hooking it up to a TV via hdmi through the port. I know that nvidia 8600's had a major problem but I didn't think the 9400 did. it get's pretty warm on the bottom too, but the fans are running I might try to "reflow" the board (stick it in the oven for 7 minutes at 375) to see if that helps. Or maybe I just take the heat syncs off and apply new thermal grease..I can't figure this one out. There are no signs of water damage I never spilled anything on it..
SMC reset
http://support.apple.com/kb/ht3964
PRAM reset
http://support.apple.com/kb/ht1379
Yes I have tried both. no success. If it was anything related to my board you would think that the video out wouldn't work when hooking it up to a TV via hdmi through the port. I know that nvidia 8600's had a major problem but I didn't think the 9400 did. it get's pretty warm on the bottom too, but the fans are running I might try to "reflow" the board (stick it in the oven for 7 minutes at 375) to see if that helps. Or maybe I just take the heat syncs off and apply new thermal grease..I can't figure this one out. There are no signs of water damage I never spilled anything on it..
Before you get into solder reflow do you run a program like iStat Menus that you can monitor temps with? It will tell you if things are running too hot without needing to apply new thermal paste.
If you decide to replace the thermal paste I recommend Arctic Cooling MX-2 paste. Easy to find and fairly cheap and great performance. I always have a couple of tubes around.
http://www.hardwarecanucks.com/foru...tic-cooling-mx-2-thermal-compound-review.html
I am not aware of the 9400 having the same BGA solder issues that the 8600m had on the earlier MBP. Question: Does it go dark at about the same time regardless of whether the machine is warm or cold? If it is thermally related it should happen at different times. The backlight circuit does include a feedback mechanism to measure its output voltage and current so it is possible it is not happy with the current flow and is shutting itself down.
It happens right when the os is loaded so I don't see the OS/Dock all that. The only thing see everytime is the gray screen with apple logo at the boot and then it goes blank.
It happens everytime consistantly. I have noticed if I hit keys on the keyboard I see the screen twitch but nothing to where I can see any images. sometimes I hear the harddrive look like it shuts down but the light on the front side stays on. I will take a video and post it up. I have seen many people who experienced this problem. This might help them as well.
Yes it it goes dark the same time everytime. I don't get to see the screen after boot, unless I hook it up to an external source.
This feedback mechanism, is it the number 7 on the schematic you sent me?
What is the voltage supposed to be? I am curious if I can bypass it to see if it triggers anything
well when it is plugged into a external output I have no problems.
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Just had a thought... If the keyboard button for dimming the display is stuck on then it would behave this way. The backlight would be on until the OS booted to the point of listening to the keyboard brightness request. It would then rapidly dim to zero. Only way I can think of to test this would be to disconnect the keyboard flex cable and then boot up with external keyboard. The trick is getting the Macbook to start up since the "on" button goes through that same flex cable. You would need to identify the 2 points on the board to short to turn the Macbook on. They do exist on the 13" so I assume they are also there on the 15".
As far as the voltage output on point 7 goes that should be around 12V. Probably 12.5V going from memory. That would stay at 12V even if the backlight dims however. The WLED driver chip would turn off the brightness through it's drive of the output FET/Caps/Diode.
Hi,
I'm new to the board and I've been reading this thread from page one to here. I've learned a lot about how LED back light works and I hope I can fix my damaged Macbook Unibody (white, not pro) with your help. Basically, I have the same problem as westbound (see here :here ).
Water damage and no back light. Everything else is OK. I've tested the fuse impedance, and it seems like the fuse is OK (very low impedance). I've read in this thread (see here) that the WLED driver had 6 pins connected to the ground and that a continuity test between ground and on all the pins should give 6x beep. If more, then the WLED driver is dead.
Can someone confirm that? My tests beep on all the pins of the WLED driver.
Are they some more tests i can run to test the driver's integrity ?
Thanks a lot to all the contributors!
I'm new to the board and I've been reading this thread from page one to here. I've learned a lot about how LED back light works and I hope I can fix my damaged Macbook Unibody (white, not pro) with your help. Basically, I have the same problem as westbound (see here :here ).
Water damage and no back light. Everything else is OK. I've tested the fuse impedance, and it seems like the fuse is OK (very low impedance). I've read in this thread (see here) that the WLED driver had 6 pins connected to the ground and that a continuity test between ground and on all the pins should give 6x beep. If more, then the WLED driver is dead.
Can someone confirm that? My tests beep on all the pins of the WLED driver.
Are they some more tests i can run to test the driver's integrity ?
Thanks a lot to all the contributors!
This is best thread ever! I have saved lot of money with couple of 13,3" MPB's. Now i'am working with 13,3" non pro alu. The fuse seems to be ok, but there is something else with it. Without schematics its little bit hard to figure out. Does anyone have schem or hint where to measure with this different led driver?
A little up. Anyone can give me a hand please?Hi,
I'm new to the board and I've been reading this thread from page one to here. I've learned a lot about how LED back light works and I hope I can fix my damaged Macbook Unibody (white, not pro) with your help. Basically, I have the same problem as westbound (see here :here ).
Water damage and no back light. Everything else is OK. I've tested the fuse impedance, and it seems like the fuse is OK (very low impedance). I've read in this thread (see here) that the WLED driver had 6 pins connected to the ground and that a continuity test between ground and on all the pins should give 6x beep. If more, then the WLED driver is dead.
Can someone confirm that? My tests beep on all the pins of the WLED driver.
Are they some more tests i can run to test the driver's integrity ?
Thanks a lot to all the contributors!
I'm going to try a different macbook pro keyboard a 13.3 to test it to see if this is the problem. I have my suspicions after you brought up the keyboard issue cause I noticed the backlight isn't working on the keyboard on the boot screen or even when it gets to the dock and wallpaper screen even though it's blank it should show keyboard back light. and I will post a picture of the jump points for the 15 A1286 2.53 board for people on here just in case they don't know where it is located.
I changed my account settings to "allow other users to send you email" but I do not know if that worked. I also am unable to view the "private messages" folder in my account, most likely because I am a new user.
I will try sending you an email, I think i was able to get it from your profile. My email is this username at yahoo as well.
Hi Dadioh. I was wondering if you could help me out. I have a macbook pro 13 mid 2010. In the process of fixing my Lion wifi issue, I accidentally broke the lvds connector on the logic board. I attempted to remove the connector but managed to strip the pads off pin one.... I was wondering if you can help me out by looking at the schematic and letting me know what pin does and where I can reroute the connection. Thanks.
I took someone else's pic and marked pin 1. please help.
I took someone else's pic and marked pin 1. please help.
Attachments
The top of the connector is pin 30. The bottom is pin 1.
Pin 1 is ground. Pin 30 is not connected.
just as I thought. I tried to trace it but it lead nowhere. I guess I am in luck. Thank you.
That is probably why it came off in the first place. Solder pads that are unconnected have no tracks to dissipate the heat from soldering. So they heat up fast and can detach from the pcb.
Out of curiousity what is the lion wifi fix? I seem to recall seeing it in post headings but I don't have an issue with any of my macs so I didn't dig deeper. Are you saying there is a hardware defect that shows up in lion but not leopard?
Just tried a different working keyboard and no luck, same thing is happening.
Just found out what is happening. The system doesn't go blank I had the light pointed on it and after the boot screen with perfect backlight it goes to startup with dock and you can see it for 3 seconds with no backlight then blanks out to white screen and system goes to sleep (harddrive stops) hit a key and the system starts again no backlight and you see dock but after 3-4 secs the screen goes white screen (no backlight still) then sleep again. It keeps repeating. I don't know what to check. Can I have accidently put the fuse in upside down? is the color side supposed to be up or is the clear side supposed to be up? Or is something else burned?
The fuse doesn't care if it is upside down. If it blew then you would get no backlight at all.
Very odd behaviour. The fact that you get a backlight at boot means that the backlight circuit is functioning normally. The SMC (system management controller) is able to enable or disable the backlight so it sounds like it is deciding to turn it off. If I had to guess it sounds like the sleep circuit is out of whack. Can't remember which model you have but on the 13 unibody pros it is built into a flex cable that goes to the battery indicator light. I once pierced this cable putting the battery screw back in and had to replace it. You could have a damaged cable.
Hi,check your lcd cable very close with a magnifying glass.I had one of the little pins bent & touching another pin & it would do the same thing.Good luck
I have used two different cables and screens and I'm getting the same thing. This would cause it to go into standby mode?
I have the A1286 15.4 unibody 2.53ghz. The cable you speak of is it the flat one that sites under the HD? I will look at that.
hopefully Dadioh can help with my issue. on a mid 09 a1286 2.53ghz, i located the 0402 fuse with the dot. it was properly identified in an earlier post, and its showing on my multimeter that it is not blown. is there any other fuse to check regarding the WLED circuit?
i am having the same issue as others on this thread. computer is fully functional, minus the backlight. thanks for any assistance!
i am having the same issue as others on this thread. computer is fully functional, minus the backlight. thanks for any assistance!
I believe it would show the apple logo then go white & either go to sleep or shut off.
Dadioh maybe onto something with the sleep flex cable.On my late 2008 15 inch unibody the sleep flex cable goes under the speaker then under hard drive to get to white sleep light on front.Maybe try booting computer with flex cable unplugged from mobo.Good luck