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?

 

[Chuck60]

Thank you sorry for the late reply. I put this board aside. To finish some other work. The issue was with graphics. 1 Ram slot is also dead. I repaired some traces near the memory module freed some melted pins on memory slot and Still nothing. Bottom slot is not detected. I?m trying continuity between memory module and pin on the board. Also checking each slot connection to logic board from memory module.

 

[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...