820-3023 No damage, 3 RAM beeps

[Jay]

History unknown but no signs of liquid damage or drop damage to the case. 3 beeps on boot and fan goes 100% within 20 sec. No solder balls around RAM area or CPU area. From another post I read "I just know that 3 beep boards when L7330 has 1.5V are a nightmare." I get 1.5V on L7330...

smiba ​​Also another post from smiba "Lots of Macbook Air 13" 2011's with ram issues"​​​​​

I find no other posts with RAM beep issues apart from those two. Has this apparently common issue been resolved by a known fix or is this a "don't bother just go on to the next repair" kind of deal?

CPU gets hot, all RAM modules feel equally hot as well and power draw on PSU is just under 1 amp.

 

[Sykulski]

It is probably the Cougar Point PCH that's failing. The known permanent fix would be replace the PCH as reflowing it is temporary (because it is a FCBGA).

 

[Gurmon]

Memory is connected to the CPU.
Dont reflow the CPU or PCH, you need to rule out the RAM first, since you have already confirmed voltage to the RAM, Your looking at bad RAM chips or at least one with a cracked solderball.

 

[smiba]

You're witnessing a dead PCH most likely, most of these devices that suffer from this issue have a PCH thats getting ungodly hot when you boot up the device.
All the issues are slightly different though,
Some have a PCH that gains heat very fast which means the device will work for 30-60 seconds until the PCH gets above its working point which then will result in the 3 beep issue. (I managed to keep it running for 3 minutes by having a big heat transfer pad on it using the casing as a heatsink)
Some have a PCH that just feels like its on fire every single time you boot it and it will always show the 3 beep issue
Some have a non-burning PCH but still suffer from this issue, I've not seen this one a lot but the few times it did some idiots already tired to reflow the CPU so I don't have enough info on it. Might as well just be a burned away CPU and its not related to this issue

I feel like most of these issues are PCH related and because communication between the PCH and CPU is failing it will give you the 3 beep issue. Replacing the ram most likely does not resolve your issues

If you replace the PCH and CPU, I'm betting it would work again

 

[dukefawks]

Hopeless. Dead RAM, bad soldering, bad traces or dead CPU. Take your pick but any of them would be a write off.

 

[Jay]

Thanks for the replies gents, this one went into the no-fix bin. Case closed.