820-00165. Onewire LED but no fan

[joshAU]

Hi again.
I have a 820-00165 that came in with a very small amount of water damage, but very little sign of corrosion.

Originally completely dead, but I found a tiny amount of corrosion on J9500, specifically around pin 19 SYS_ONEWIRE.

I cleaned and reflowed, then added some enamel wire and successfully fixed the onewire break...

I now have the Onewire LED on charger, but still no fan.

SMC reset changes LED colour from orange to green, then back to orange, correctly.

PPDCIN_G3H seems a bit low at 15.07, but is the same with two known good genuine chargers.
I also tried with another power daughterboard and flex cable that connects to J9500, with no change.

PPBUS_G3H, PPBUS_S5_HS_Computing_ISNS and PPBUS_S5_HS_OTHER_ISNS all 8.61v
PP3V42_G3H 3.42v
PPVRTC_G3H 3.34v
PP5V_S5 5.03v
PP3V3_S5 3.35

PM_BATLOW_L 3.3v
SMC_ADAPTER_EN 3.43v
PM_DSW_PWRGD 3.43v
PCH_DSWVRMEN 3.23v
PM_RSMRST_L 0v
PM_PWRBTN_L 1.01v

Any suggestions greatly appreciated.

 

[2informaticos]

Test the board without LIO flex.
Magsafe light is not needed to turn on the board.
Do you get 3V3_SUS?
Check the 4 PCH's RTC signals.

 

[joshAU]

Hi again 2informaticos.

I removed LIO flex.

No PP3V3_SUS.
I checked P3V3SUS_EN = 0v
PM_SLP_SUS_L = 0v

In regards to checking the 4 PCH's RTC signals... what pins should I be reading with an oscilloscope?
I can only see PCH_CLK32K_RTCX1 in the board view...which I should be able to get a probe on at U1900.

 

[joshAU]

Is this correct?

PP3V3_SUS is created by U8020.
U8020 will only create it if:
PP3V3_S5 is present AND if P3V3SUS_EN is present.

However, P3V3SUS_EN is 0 Volts.

P3V3SUS_EN requires PM_SLP_SUS_L, via R8190.
R8190 measures 98ohms, so is OK.

PM_SLP_SUS_L comes from the CPU U0500... and as there is no short to ground on PM_SLP_SUS_L, does this mean the CPU is not creating PM_SLP_SUS_L?

What requirements are there for U0500 to create PM_SLP_SUS_L?

Or does this suggest a cooked CPU?

Thank you once again.

 

[2informaticos]

"4 PCH's RTC signals."
If you look inside PCH schematic, I'm sure you will find the signals.
RTC block is clearly marked (page 12).
No need of o-scope, these are DC signals.

 

[joshAU]

There's so many CLK lines on there ahhhrrrrgggg...
Do you mean these ones below?

PCH_CLK32K_RTCX1 = 0.35v
NC_RTC_CLK32K_RTCX2 = CANNOT LOCATE ON BOARDVIEW!!!
HDA_BIT_CLK_R = 0v
TP_PCH_I2S1_SCLK = 0v

For some reason, NC_RTC_CLK32K_RTCX2, while it is listed in list of nets in the boardview, I cannot locate it on either side of the board?


Either way, I'm rapidly running out of time, as work closes in 2 hours 15mins, lol... so I guess I'll have to leave this one to next year.

Thanks for your help, on this, and on numerous other occasions, 2informaticos, I really appreciate your advice.
Have a good Christmas and New Years!

 

[2informaticos]

To be more explicit:
RTC_RESET_L, PCH_SRTCRST_L, PCH_INTRUDER_L and PCH_INTVRMEN.
All them are connected to a clearly delimited RTC block inside PCH.

 

[piernov]

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