Apple MBP 13" 2011 820-2936 - Beeps - Memory and socket ok

[Roman78]

Now before I go further with this one: https://www.badcaps.net/forum/showthread.php?t=85147 I just got one with quick a simple issue.

A MacBook Pro with a Memory issue. Sometimes it just beeps 3 times, sometimes its boots and crashes beeping and distorting video output. So first thought defective memory, so i replaced it with know working one, same issue. So i thought bad memory socket, so I just installed one module in each socket separately, same issue.

Now i noticed when pushing the Logicboard on certain spots, it just crashes, so it must be a bad connection on the LB somewhere. I just took a look at the brd file of the board, but the Memory got 210 connections on the LB.

I already resoldered the U7300, it is around this area somewhere. Could be on the other side.

What could it be? How to find the lose connection?

[piernov]

Re: Apple MBP 13" 2011 820-2936 - Beeps - Memory and socket ok

You can check that you indeed get stable 1.5V and 0.75V on the RAM, but I'd say both RAM slots are probably bad (or rather broken solder joints/pads). Pretty rare but can happen. You can at least inspect the visible solder joints of the RAM slots under the microscope to get an idea.
Could also be the CPU.

[Roman78]

Re: Apple MBP 13" 2011 820-2936 - Beeps - Memory and socket ok

I already checked the visible solder points, as far as i could see, they look good.

[Roman78]

Re: Apple MBP 13" 2011 820-2936 - Beeps - Memory and socket ok

I doubt both ram-sockets are bad. While installed in the top socket, i can wobble the module without any problem. But when pressing on the Logicboard the machine crashes. I had a look on all connected parts and pressed alls those, but they seem all alright. So i think it could be the CPU. I will try to reflow the CPU.

[Roman78]

Re: Apple MBP 13" 2011 820-2936 - Beeps - Memory and socket ok

So, update. I reflowed the CPU and i was able to work on it for 2 hours. I'll test the machine for some more days.