[SOLVED]820-00165 - Brain dead.

[gcain]

Doesn't perform an RTC reset, fan turns on to about 50% throttle, after a short while it goes to 100%.


CPU Stays cold, checked for PPVCOMP_S0_CPU and it's 0.2V.

 

[gcain]

PPVCC_S0_CPU is 0V too.

 

[JohnB8812]

There is no possible way the fans are spinning if CPU VCore is missing....resistance to ground on VCore? Any other rails missing?

 

[gcain]

The board seems to be dead now.

Will go back to basics and measure on all the rails.

Something seems to be warm around the SSD jack, but I can't find exactly where it is.

 

[dukefawks]

CPU Vcore is NOT needed for the fan to spin! What the hell is an RTC reset?

 

[JohnB8812]

"CPU Vcore is NOT needed for the fan to spin!" -My Bad did not know that. Question would be any history on this? Liquid, drop, random death etc?

 

[gcain]

What the hell is an RTC reset?

The three fan spin it does when you first connect power again.
If you call it something different, let me know.


There is no history with this board. Customer said he was using it and it died mid session.

 

[phuketmymac]

Hey gcain,

It seems you haven't worked on a 820-00165 yet... these boards don't "Fan spins 3 times" like a 820-3437 would. Only once.
Plug a battery and check for Vcore again.

If no vcore, check resistance to ground on vcore and report.

Do you get the screen to light up at least when the span is spinning?

 

[gcain]

Thanks, I hadn't noticed that before.

Board behaviour has changed a little over night.


Screen does not light up, USB mouse doesn't light up. The fan spins for a few seconds then it dies for a few seconds, then repeats.

PPBus : 8.58v
PP3v3_s0 = 3.3 (when it's running, drops to 0v)
PP3v3_s4 = 3.3 (when running)
PP3v3_s5 = 3.29 steady.

 

[gcain]

CPU VCore at L7310 & L7320 is fluctuating but mostly at 0v.

Would't it simply be a symptom of the other power rails fluctuating?

 

[dukefawks]

Try BIOS to rule that out first.

 

[gcain]

So I swapped the bios with a donor, and I get a flashing folder.

Can you explain what happened? Corrupt firmware? And how can I detect that in the future?

Do I need to clean the ME now?

I could read the firmware off the other chip, but if it's damaged, what's the point. I know the serial number.

 

[dukefawks]

Upload original dump

 

[gcain]

Thanks Duke.

https://drive.google.com/file/d/1i6fbK7uKbmnWhwCg9XzbiqawfDcjCpIH/view?usp=sharing


Did the firmware just get damaged?
Just wondering how that could happen.

 

[gcain]

Is anyone else able to clean the ME region on this please?

The customer is starting to become a little painful.

 

[gcain]

Got this one to work in the end.

Please mark solved.