820-2915 No PP5V_S3

[RyanLEN]

Hi. No liquid damage. Looks like SMC was replaced. Original the fan would spin once for 3 seconds but not recently. All power rails are present up to PP5V_S3. Diode mode 0.412. Have 12.6V on 23 of U7201. SMC_PM_G2_EN is 3.4.V. Missing PM_SLP_S4_L. Diode on this line is .480. Thanks for your help.

 

[smiba]

PM_SLP_S4_L missing issue is always a pain in the ass, as usual check bios termination resistors and PCH clock

 

[RyanLEN]

Thank you Smiba. appreciate it. Kind of unsure where to locate but will figure it out. Thanks again.

 

[dukefawks]

What is the history? Is the SMC correct for this board?

 

[RyanLEN]

Smiba- Termination resistors (if Im in the right spot) are 47 .Ohm


Hey Duke.
Not sure on the history of computer to be honest. Board looks very clean in the way of liquid damage. Only minor discoloration to the right of U6100 (if the SMC was on your right side) No other obvious damage jumps out at me. Im assuming SMC is legit. There was something on it that looked like flux but turned out to be nothing. Thanks, have a good one.


PPBUS - 12.6 V
PP3V42 - 3.42 V
PPVRTC - 3.42 V
PP5V_S0 - .007 V
PP3V3_SUS - 0 V
PP3V3_S5 - .768 V
PP3V3_S4 - .768 V
PP3V3S3 - O V
PP3V3S0 - 0V

 

[smiba]

Why is PP3V3_S5 at 0.768V? You need to fix that first before we can get to S4 or S3

P3V3S5_EN high? If yes what's the resistance to ground on PP3V3_S5?

 

[RyanLEN]

Isnt PP3V3_S5 created at U7201? Same as PP5V_S3? If Im missing PM_SLP_S4 then how can this be fixed. Or will the chip create PP3V3_S5 seperatly? Which in turn could supply U9550 which then could help with my PM_SLP issue? Im not at work right now, but I remeber checking P3V3S5_EN high and I believe it was 3.42 V. Looking for datasheet on U7201. Thanks for the help.

 

[smiba]

PP3V3_S5 is created at U7201, but without having all the S5 power lines the chip won't even be told to generate PP5V_S3.

Without PP3V3_S5 being at ~3.3V the system simply won't go any further, big chances that solving this issue will also bring PM_SLP_S4_L.

If P3V3S5_EN was high (>3V) check the resistance to ground on PP3V3_S5 to see if its a (semi-)short.
If its not, fair chance that replacing U7201 will solve your issues

 

[RyanLEN]

Thank you. Im sure you are busy. I appreciate you taking the time to reply and your explanation is helpful. I will check tomorrow. You have a great night/day.

 

[RyanLEN]

Diode mode PP3V3_S5 - 130V. Replaced U7201 and I now have PP3V3_S5 at 3.3 V. Fan spins once around and stops. Unfortunately still do not have PM_SLP_S4_L.


PM_PCH_PWROK - 0.001V.


U2800

Pin 16 - 0 V
Pin 15 - 0 V
Pin 14 - 0 V
Pin 13 - 3.4 V
Pin 12 - .386 V
Pin 11 - 0 V
Pin 10 - 0 V
Pin 9 - 0 V
Pin 8 - .036 V
Pin 7 - 0 V
Pin 6 - 0 V
Pin 5 - 0 V
Pin 4 - .075 V
Pin 3 - 0 V
Pin 2 - 3.3 V
Pin 1 - 3.3 V

Thanks.






Thanks.

 

[smiba]

If the fan spins around once it means you've hit a S0 state, but something goes wrong after that and it falls back to S5. (PM_PCH_PWROK is probably is high for a split second)

Because the system goes back to S5, PM_PCH_PWROK becomes low again. Its a signal thats only there in a S0 state
U7201 is most likely not the issue anymore and is working

Does PPBUS_G3H stays stable at 12.6V? (Check this while plugging in the charger to see if it drops while the fan spins)
Also check R1800/1/2/3 if they're high

 

[RyanLEN]

OK. Will check this out in the morning. I have frequently measured G3H and Im pretty sure its around 12.56 V with the fan off. But will do like you said and double check and check those resistors. What about PM _SLP_S4_L? Shouldnt that still be present while in an S5 state? Thanks a lot man. Have a good one.

 

[dukefawks]

If the fans spin then ALL_SYS is coming high and all voltages are present. The only one missing could be CPU Vcore or GPU Vcore. Has the GPU been messed with?

 

[RyanLEN]

Hey Duke. It very well could have been now that you mention it.. Thermal compound doesn't look original. Some discoloration. But board is clean and edge bonding still on. Doesn't mean someone didn't hit it with a paint stripper I guess. I will look closer tomorrow. Thanks.

 

[RyanLEN]

Hi. G3H is steady at 12.56 V.

R1800 - 3.242 V
R1801 - 3.050 V
R1802 - 3.337 V
R1803 - 3.337 V

Thanks.

Duke. You mentioned GPU Vcore. Doesnt it need PP5V_S3 to function? Which I am missing.

Thanks.

 

[dukefawks]

The fans are spinning right? That means all power is fine. If GPU is shorted the board will shut down when GPU Vcore is turned on.

 

[RyanLEN]

Ohhhh. I seeee. lol. Thanks Smiba for all your help and info very appreciative. Duke... Till next time.