A1534 2017 Macbook 12" Retina famous flashing folder cannot see ssd

Good morning all. Yes this is a common issue, most of the time bad CPU right?

However, on this one all of my ssd power rails are dead. Does the cpu still cause this to happen. I though the last few that did this I had all of my ssd rail powers, but not this one.

Is there a possible common thing that can cause no ssd rail powers?

I would really like to see if I can save this one because it is rare I thought for one of these to have the i7 chip and 16gb or ram.

FYI when connecting a usb with high sierra on it it works fine with no problems.

Thanks
 

2informaticos

Administrator
Staff member
Any short on SDD power rails?
Check for enable signal of these power supplies.
Any history available?
 
Thanks.

I do have a short on only 1 of the rails:
PP0V9_S0SW_SSD_CORE .001 diode mode .2 ohms
Verified with a working board same measurement on that line was .224 diode 365 ohms

Any suggestions?


There are alot of caps on that line? Also of course the ssd chip itself.
 

2informaticos

Administrator
Staff member
Very likely dead U8600.
You can inject voltage, no more than 1.2V.
I hope you have a 10-20A PSU for test.
 
All I have is a 5amp max. Tried it not much getting hot yet. The U8600 (SSD chip) not even warm??? I take it that's why I need more amps to blow the chip off the board :)
 

2informaticos

Administrator
Staff member
You have almost pure short.
0.2 ohm requires 5A at 1V and you cannot increase the voltage.
Your PSU may be already stuck on 1V and will not inject anything in fact.
5W should be good enough to detect some heat...

Try with 0.8-0.9V and let time to heat something.
Let amp limit at max, of course; 4-4.5W can heat something too.
 
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