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Zack
1
Asked
Why does my MacBook Pro turn on and then off again?
HI, I was currently trying to ask this in another persons question "how to troubleshoot my logic board" Ok here's the details, first my mac has ran fine for almost 3yrs (A1260), no previous repairs, no spills or neglect. I woke up a couple of weeks ago and tryied to turn it on and all I get is the - led light, no chime,no video. Harddrive, fans, & dvd drive all start up, solid green light on power supply (or amber when battery needs charged) seems like it charges it fine though. Then within a second or two turns off likes it's not getting power. I thought it was the battery when it happen so i bought a new one because my old one was shot, power supply is 85w & about 6mo. old. Apple of course says it's the logic board, I do not agree. I've tryied resetting PRAM, SMS, holding C, reinstall disc (I have Leopard 10.5.6) removed the battery tried w/ magport only & vise versa. When I take out the Ram the computer will stay on and just beep indicating No Ram so it past that. I've disconnected everything from the logic board except the left i/o cable or it will not even attempt to start w/o it. But same problem. If I hold down the power button it will stay on for a few seconds longer, but with the same result except the led at the end will flash fast several times and then shut down. I have not taken the logic board completely out yet or tryied to clean it, I am waiting for my tool kit I just ordered from here. I think it has something to do with the left logic board or a bad cable, but I can't be sure. I have look and scrolled through this site and have found a number of people having the same issue or extremely close to it, but can't seem to figure out the exact point of promblem - some peoples have just started up again, other when it's cold, or hot. I love my mac and refuse to buy a new one when I know theres a solution. I hope this is enough information, please any help would be greatly appreciated and thanks in advance.
Edited by: Walter Galan ( )
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mayer
148.1k
Answered
You've done a good job running diagnostics. Just a couple of things I might try. Pull both RAM sticks and reseat them just one at a time in each of the slots to both test the RAM and the slots.
I would also replace the PRAM battery: MacBook Pro 15" (Models A1211/A1226/A1260) PRAM Battery
MacBook Pro 15" (Models A1211/A1226/A1260) PRAM Battery
Keeps track of dates and other system information while computer is powered off — 12 available at 39.95 each.
Thanks Mayer, I have also tried the seating of both RAM sticks, and tested them both by themselves and in different slots, but no luck. I was thinking the PRAM battery might be the problem as well, I will try that. I did unplug it for a little while and then reconnected it to the l/b, hoping it would reset it manually, but that didn't do the trick. I'll have to get that ordered. Thanks and if you think of anything else let me know.
Zack,
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Mark
45
Answered
You said you tried mayer's advice in the other thread suggesting to check the pins on the power adapter for being loose? Have you tried another power supply? I know when I brought mine into the Apple store they used theirs so that threw me off. I still don't understand how my issue appeared to be power related when, like you, I was still able to get a solid green light and charge my battery. When I started to test each piece connected to the logic board I started getting funny responses from the adapter. It would be feint green at times, when I'd trip the power pads, it would blink orange, sometimes it was solid green. I would disconnect the whole I/O board and then reconnect it to make sure all the connections are good. I feel like mine might have been loose somewhere. Hold the adapter to the port physically to make sure its connecting properly. It seems like its getting power initially but theres a weak connection somewhere.
Hi Mark, I haven't tested it with a meter but I did take a look, I tried cleaning the port though. I haven't tried another one either but I will see if I can get ahold of one. I also haven't got the funny colors like you, sometimes I will not get any light at all though, but the battery still seems to be charging (blinking underneath) when I get my tool kit in I will take all of the connecters and left i/o board out to see if they're all tight and make sure theres no visable damage. Thanks and let me know if you can think of anything else in the mean time.
Zack,
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Answered
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paul
1
Answered
I've replaced the PRAM battery, it didn't work for me.
Zack, after the some more research, I believe the problem you're describing ( I have exactly the same symptoms, including the beeping when removing the memory chips) is related to the NVIDIA 8600GT graphics processor overheating and popping 1 or more of it's solder connections.
Jordan, the problem you're describing is almost certainly the famous NVIDIA 8600GT issue.
Hi Zack - I'm having the exact same problem as you with my MBP A1260. Any luck determing the cause? I'm scheduled right now to take it to the Apple Store on Friday (I have a lot of PC hardware/softwa
Bryan,
I have also exactly the same problem/symptom
Michael Walgram,
Im having the same problem now. i know its late but I tihnk it might be your macbook pro ran out of thermal paste. the thermal paste is what keeps the macbook at a certain temperature. and when it runs out the computer can reach a certain temperature and when it reaches this temperate it has sensors telling it to turn off before it frys your logic board or anything else.
aljwanna,
Did you ever figure this out?
tomyg,