820-00840 Missing SSD EN

[Vertx]

Hello!,
Got this 820-00840 which had damaged SSD connector and few knocked off caps around it. Replaced SSD connector, turned on and off few times to test it and it was booting all fine, so decided to test fully with connected trackpad keyboard and speakers, after putting board back to housing it was coming on with question mark again.. And on top of that when i tried to boot to mac os x pendrive smoked (but not sure if the problem is new USB C to USB Adapter).
SSD_PWR_EN_L Missing
R8640 - 68K instead of 100K
R8645 - 20K instead of 100K
R8620 - 94K instead of 470K
All caps connecting with U8640 looks good.

Any ideas where to have a look? . As always appreciate any help!

 

[2informaticos]

If smoke, should keft some sign; if was on the board.
Does the board still work now?
Did you try again to boot through USB?

High value resistors will show lower value measured onboard.

 

[Vertx]

Board still works/boots to usb only not ssd - question mark. Flash drive burned down. Still on this board I think values of resistors are too low as on working board as checked they go up to 100k and that one R8620 over 400K, any ideas why on this one values are so low?, what could I check, please?

 

[2informaticos]

What kind of USB-C hub used?
Did you try another?
USB flash drive got burnt when charger was connected too?

 

[Vertx]

Used this one https://www.amazon.co.uk/gp/product/B015Z7XE0A/ref=ppx_yo_dt_b_asin_title_o03_s00?ie=UTF8&psc=1. But usb c adapter works still fine, board kills whatever is connected to it and has IC's (maybe instead of 5V it gives all around 20V?). Yes, I tried another one usb c adapter and different flash drive, same results (another one burned flash drive). Looks like It also kills ssd's connected to board. Used only charger to power on machine.

 

[2informaticos]

Check if your input MOSFETs are not shorted IN-OUT (Q3100/200).

 

[2informaticos]

Input MOSFETs are not related with SSD in anyway.
That higher ohm value on SSD_PWR_EN_CONN_L can be sign of bad solder at U8640.
Strange to get lower value in diode mode.
Change U8640 again.
Be sure R8640/45 have correct values, measured out of board.

 

[Vertx]

All problems sorted, just need to fit new keyboard and will be as good as new. Finally found out that some of this model boards does not suppose to have U8640, R8640, R8645, R8637 mounted, so removed these and finally machine boots to SSD!, Thank you 2informaticos for your guidance and time, really appreciate it!