Macbook Pro Freezes When Testing Memory (Internal Diag and ASD)

[Agent]

I have a Macbook Pro with BGA RAM. It fails to boot up. When I use the internal test diagnostic, the computer always freezes during memory testing. I have the EFI Apple Service Diagnostic. When I boot up ASD3S155, If I deselect the RAM tests everything passes without issue. I can not get the RAM tests to pass. Every time it gets to MP(Multiple Processor) memory test, it completely freezes up. (It doesn't get far enough to say it failed) I do not have a re-flow oven and my guess  is a bad solder joint? I have considered hitting it with a heat gun, but figured I would stop by here first to see if anyone had a better idea.

[petercut62]

Hello,
Have a look to Louis Rossmann channel on YT.
https://www.youtube.com/user/rossmanngroup/videos
It might be helpfull
Regards

[tooki]

I think it’s rather unlikely to be a failed solder joint (though it certainly is possible) — I’d suspect a dud RAM chip.

Either way, depending on the age of the machine, it might be worth repairing, or it might be cheaper to buy another unit of the same model on the used market.

[wraper]

If that was a bad solder joint, none of those tests would pass. Considering the test it fails at, it could be bad CPU.

[Agent]

Yea that does make sense. It would likely fail all the memory tests. I got the unit for nearly free, so I'm open to any possible repair. I don't care if I end up making it worse. It's useless in its current state.

Also after talking to some people, the reasons it fails to boot may be a bad GPU. https://www.apple.com/support/macbookpro-videoissues/
They said the ASD doesn't catch everything. I have one of the models listed in the link.

[kripton2035]

what macbookpro model is it exactly ?

[Agent]

what macbookpro model is it exactly ?

Retina 15 inch Early 2013

I booted into verbose mode and after about a minute, the text becomes all jumbled. Starting to look like a graphics card issue?

[kripton2035]

yes could be those retina 15 from 2013 have a recall program for graphic issues.
you should go to an apple service center, the motherboard exchange is free if the graphic card test program says it's concerned.
valid to 4 years after purchase if i remember correctly.
send me a PM with the serial number I can check the purchase date for you.

[Agent]

yes could be those retina 15 from 2013 have a recall program for graphic issues.
you should go to an apple service center, the motherboard exchange is free if the graphic card test program says it's concerned.
valid to 4 years after purchase if i remember correctly.
send me a PM with the serial number I can check the purchase date for you.

4 years is correct. I talked to apple and my purchase date was July/02/13. Out of curiosity how do you check the purchase date? If you go to checkcoverage.apple.com it doesn't list it...

[kripton2035]

there is a web site for apple certified people only where you can see the purchase date, and all the repairs that have been done on a mac.

[Rasz]

Luckily, RAM is easy to replace as it's usually in 0.8mm FBGA package, not those 0.35mm/0.4mm damn CSP.

8? 16? 32 chips?

[Armadillo]

It's better to check the 1.35 volts DDR3L power supply voltage first [ripples].

[Agent]

It's better to check the 1.35 volts DDR3L power supply voltage first [ripples].

Do you have a pin-out or a test point? I have a scope and can check it out. If I upload a scan of the board can you point it out?

It's almost certain a dead RAM chip.
I have a couple of bizarre problems before with my various computers, and almost every time if something can't be explained, a RAM swapping took care of it.
Luckily, RAM is easy to replace as it's usually in 0.8mm FBGA package, not those 0.35mm/0.4mm damn CSP.

Is there anyway to identify exactly which chip it is?

[Armadillo]

Do you have a pin-out or a test point? I have a scope and can check it out. If I upload a scan of the board can you point it out?

See the capacitors labeling? Alot of them to smooth out the ripples.
I think the problem is, not fully dead, if fully dead, easy to find, half dead is more difficult.
Trace it when the mac is doing some dynamic activity, not static.
Its easy to say scope it until you actually do it, it's smd.
For the pros, they will put a DDR3 dummy loads onto the bank using dummy DDR3 fixtures.
If it's too difficult, just look for them. cheers!