[SOLVED]820-3476 - fan spin - no vcore

[jamiehorn1]

Hi all,

I have an 820-3476 that had no power missing pm_slp_s4_l.

Traced that back to a corroded U8020.

Now it spins and draws 0.14 amps. I have no vcore and cpu is cold.

On Q8150 i have all the inputs around 0.7v but All_sys_pwrgd is 0.2v (i think this should be 3.3v?)

I replaced Q8150 just in case but no luck.

On U1950 i have SMC DELAYED, 3v42 and CPUVR_PGOOD_R.

But all sys is 0.2v and PM_S0_PGOOD, SYS_PWROK_R are both 0v

any ideas?

 

[dukefawks]

ALL_SYS should be present that is why there is no Vcore.
ALL_SYS is being pulled down so first measure resistance to GND on this line. Then check if all rails are actually present

 

[jamiehorn1]

Thanks Duke - U7200 had no 5v input - ran a wire and we're on!