820-00165 not booting liquid damage (T3582)

[arnonabuurs]

Hi guys I have an 820-00165 that was liquid damaged, replaced U5480 as there was the spil and ultrasoniced it board looks very clean overall. The Mac turns on and has all voltages, I can see the display turning on but no drive is recognized. External drive also does not work. Voltages I get on U5480 are 3.3v on pin 3,4 and 5 and only 0.216v on pin 6. Replaced another U5480 but same issue. Also tried to boot from external SSD didnt work either. Ideas?

 

[2informaticos]

"only 0.216v on pin 6"
That means only 36mA sinked by SSD.
However, normal value is less than 2V (aprox 3A) there; do not expect 3.3V!

"External drive also does not work"
-------
"Also tried to boot from external SSD didnt work either"
Do you mean doesn't start from USB port too?
USB mouse works?
U5480 doesn't affect USB; it is just current sensor for SSD.
SMC will not consider the sensors in SMC bypass mode.

 

[dukefawks]

Can you get to the boot menu by holding down option key? Could be possible EFI lock, PRAM reset done?

 

[arnonabuurs]

Hi Guys, sorry for not replying this board has been on my pile and I have some time to get back at it. I did a PRAM reset, connected an external USB boot drive and hold option, but no boot menu appears. No chime, do have a light on the external drive and a light on the USB mouse.

 

[2informaticos]

If you remove internal SSD board should automatically start from USB OSX.
Try one pendrive with Link LED, to confirm 100% USB activity, or not.

 

[arnonabuurs]

My external SSD drive has a led and its blinking, for sure it has power. Will check the other port as well to make sure it doesnt work on both, and report back

 

[arnonabuurs]

So it doesnt boot from both USB ports, do have a led on the drive. The display turns on, after a minute fan spins high and just keeps running like that. Could it be some resistor or line around U6100 not good, or then the display would not be able to turn on?

 

[2informaticos]

U6100 area should be good.
Do you get black screen, or "pure" white?
Or missing backlight?
I didn't exactly understood you about "display turns on"...

 

[arnonabuurs]

I mean the display turns on, it has a black backside with white logo (although obviously no logo shows, but I can see it light up as this is my testing display it has a little crack in it. Also I measure 25v on backlight pin.

 

[2informaticos]

So you don't get any image, even if let USB OSX connected few minutes?
Nor even question mark folder?

 

[arnonabuurs]

Yeah thats correct, and the fan start spin max after a short while, also when i use external KBD no menu pops up on command

 

[2informaticos]

Try new BIOS with clean ME, just in case...