820-3115 PM_SLP_S4_L pulsing

Fizzl92

Member
This 820-3115 came to me dead. I fixed a short on 3V42 and now it has quater fan spin. PP3V3_S5 is stable, PP5V_S3 is pulsing every 5 seconds cause PM_SPL_S4_l is also pulsing. Not really sure where to go from here. Any known suspects like U1950 on 00165? I did replace U7200 and clock ic so far but no change. Thanks in advance.
 

Fizzl92

Member
Thank you. Yes, ALL_SYS_PWRGD is also pulsing.
Everything above and 3V3_S5 is stable.
5V_S3, 1V5_S3, 1V8_S0, CPUVCCIO_S0, VCCSA_S0, PPV, T29BST_BOOST are pulsing.
PPBUS_SW_BKL, PPVCORE_S0, CPUIMVP_S0 are steady 0V (confirmed with scope).
Any rail/coil i forgot thats important?
 

2informaticos

Administrator
Staff member
AVREF_SMC is present?
Test if board stays on in SMC bypass mode.
Be sure R7402/03 are good; resolder them and check the traces too.
 

Fizzl92

Member
AVREF_SMC is 3.3V, steady.
R7402 150,4 kOhm
R7403 182,3 kOhm
I resoldered both.
Both have 12.57V at pin 2 steady and 12,4V at pin 1 pulsing. But i guess thats because 5V supply of U7400 is also pulsing, resetting the IC and Path to GND for TON Pins with every pulse...
In SMC bypass mode i get no green light, 12.3V (as expected) but also no start and pulsing rails.
 

2informaticos

Administrator
Staff member
In SMC bypass, still not pulsing at L7510/20?

Check U7400 pins, 46, 19, 29; should catch pulse at least.
 

Fizzl92

Member
In SMC Bypass (12.3V checked) U7400 pins, 46, 19, 29 are pulsing, as in "normal" mode before. And L7510, L7520 still steady 0V on my scope, no pulse.
 

Fizzl92

Member
Sadly the bios also did not fix it. I used the IC i made for the same board in my other thread. I dont think thats the programming but do you have a known good file for me - just in case my "good" somehow is not wotking correctly?
 
Top