A1466 820-00165 fan spin, no chime vcore present

[willumpie82]

Hi all,

I'm working on a rabbit-hole again, I have a 820-00165 board that has not been damaged (no liquid or other nasty stains).
It came with the story that it runs but freezes randomly, when we looked at it at first it came to the disk selection and then frozen now it won't display or chime at all. I removed the SSD and wifi and inserted a USB drive, no changes.

So opened it up removed the battery and when powering it on it gets fan spin but no chime and no image, looks brain dead to me...

on visual inspection the board looks mint

I Checked al the common voltage rails (mostly I just probe all coils) and look at the schematic if i see something weird.

In this case they looked fine. also the two vcore phases rails are present (1.2v). I inserted a USB thumb drive and noticed the led on it to go on and off again constantly. the CPU gets a little warm as I would normally expect. Than I took my oscilloscoop and probed the 5v usb rail which was present and stable, I also probed the bios MISO line (slave out) and there seems to be data.
to me it looks to be bootlooping but don't know why, (I checked all 820-00165 Rossmann videos but no clues)

[piernov]

Re: A1466 820-00165 fan spin, no chime vcore present

Inspect board under microscope for any hint of liquid or physical damage/knocked off component.
VCore should be 1.7V so double check that.

[willumpie82]

Re: A1466 820-00165 fan spin, no chime vcore present

Hi

The vcore rail and is is 1.8v

also verified all the other rails, all OK

ppbus_3gh = 8,57
PPBUS_S5_HS = 8,57
PPBUS_S5_HS_OTHER = 8,57
PPDCIN_G3H = 17,94
PPDCIN_G3H = 17,94
PP3V42_G3H = 3,42
PPVRTC_G3H = 3,34

PP5V_S5 = 5,109
PP5V_S4RS3 = 5,11
PP5V_S0 = 5,11

PP3V3_S5 = 3,34
PP3V3_S4 = 3,34
PP3V3_SUS = 3,34
PP3V3_S3 = 3,34
PP3V3_S0 = 3,35
PP3V3_S4SW_SNS = 3,34
PP3V3_S0SW_SSD = 3,34
PP3V3_S4_TBTAPWR = 3,34

PP1V8_S3 = 1,79

PP1V2_S3 = 1,20

PP1V05_SUS = 1,05

PP1V5_S0 = 1,51

PP0V6_S0_DDRVTT = 0,6

PP1V05_S0 = 1,049
PP1V05_S0SW_PCH_HSIO = 1,049

PPVCC_S0_CPU = 1,80

when assembled + ssd = current is 665mA

[Lukira]

Re: A1466 820-00165 fan spin, no chime vcore present

I have a board with exact same issue. Have you found a solution??

When I got the computer I noticed that the bottom case had a dent right on top of the fan and the fan housing was bent preventing it to turn. I bent back the housing and turned on the computer.
It booted normally but the screen was dark and the brightness button wasn't working.
At first I thought it was freezing because the cpu was overheating because the fan wasn't spinning but no... after that it would turn on only sometimes and when it did, it would freeze.
After that it didn't booted anymore. I have vcore phase 1 and 2 and cpu gets a little warm, fan spins but no chime or image.
The board was very dusty but no corrosion at all.