820-2915 question mark folder

[Chuck60]

Ok here?s my finding
1-new drive fresh install confirmed on another mac
2-replaced hdd cable
3-checked connectors seem fine

min looking around board for missing components. Any pointing in the right direction would help

 

[2informaticos]

Boot USB OSX and check if internal HDD is recognized on Disk Utility.
Did you try an HDD with no APFS macOS installed?

 

[2informaticos]

DDR3 tester card can show the lines with problems; usually broken solder/trace, corresponding LED stays off...

 

[Chuck60]

Ok I?m gonna search ddr tester because I tested each line and they all have continuity.

 

[Chuck60]

It?s a actual hardware or software ? I?ve seen the modules with the error codes is that what you mean?

 

[Chuck60]

Just one question I have no connection to j2900 for vref at pin 1 on j2900 but I have .75 vref at r1021. Should I not have .75 at pin one of j2900? I?m sorry for the terrible images I drop this phone in the toilet :/

 

[2informaticos]

https://es.aliexpress.com/wholesale...SB_20200502141030&SearchText=ddr3+card+tester

DDR2 maybe obsolete now, but DDR4 is more actual...