A1502 820-4924-A no SSD

hgoncalves

Active member
Hi,

I have an A1502 820-4924-A that does not recognize the SSD. First, it wasen't booting the macos (freezed in the loading bar), and after the CleanME upgrade, the SSD is not recognized any more, even with a known good SSD.

On SSD connector J3700, I have 3.3V on all pins of PP3V3_S0SW_SSD_FLT

SSD_SR_EN_L = 3.2V

SSD_RESET_CONN_L = 3.4V

SSD_PWR_EN = 0V

I have 3.2V on R1620 SSD_PWR_EN , so I think that it is not the CPU (don't know if it makes sense).

I think that it might be U8070, or U3711 or U3740.

On U3740 I have 3.2V on SSD_PWR_EN , but on U3711 I think that I have 0V on SSD_PWR_EN pin 1

Shall I replace U3711?
 
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2informaticos

Administrator
Staff member
"I think that I have"
What this mean, you are not sure about measurment???

If trace is broken , run a wire to fix the problem.
 

hgoncalves

Active member
Hi,

I said "I think" because I wasn't sure that I was reaching correctly the pin under the chip. But after all I do have continuity bettewn U3740 and U3711, and the 3.2V on pin 1 of U3711 and 3.2V on SSD_PWR_EN in J3700.

Not sure if it was the BIOS or a bad contact on U3711, but after restored the original BIOS, the mac now recognizes the disk, but freezes on the loading bar, even with another disk.

Can you help?
 
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2informaticos

Administrator
Staff member
You had APFS issue, after flashing BIOS without APFS support.
I supposed that, but you've said just clean ME, not full BIOS; post accurate information in the future.
You also left unclear if SSD_PWR_EN line wasn't broken.

Now is time to clean ME of your BIOS; or flash new one (clean ME), with APFS support.
You also have the option to install High Sierra into empty internal SSD, to get APFS support with the other BIOS tried.
 
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