820-2915 missing PM_SLP_S4_L

Chuck60

Member
Hi I have a board missing PM_SLP_S4_L
Cpu prerequisites:
ppvrtc_reset_L=3.3v
Pch_srtcrst_L=3.32v
Pch_intvrmen_L=3.24v
Pch_dswvrmen_L=.489mv
Sysclk_clk32k_rtcx1=.489mv
PP3v3_s5=3.3v
Pp3v3_sus=2.7v
Pm_batlow_L=3.3v
Pm_rsmrst_L= 3.4mv
Pm_pwrbtn_L=3.45v

I also have power u6100 on pins 8,5 but not on pin 1 (SPI_MLB_CS_L)=.489v

Shouldn’t the bios output 3.3 on pin 1 ? Is it a bios or Should I try that trick of hearing cpu like on the last board?
 

2informaticos

Administrator
Staff member
Broken trace???
Pin 2/R1915 is PCH_DSWVRMEN.
Where did you check it before, as that is the only point accessible???
 

Chuck60

Member
I’m sorry I was Hurricane preparing. no it’s was a bad solder joint. It’s good now r1915 pin2=3.2v checked it multiple times. Touched up the joint. Now on to why my Pp3v3_sus is low
I’m going to check the Level of Q7802/20 voltages.
As you suggested
 
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Chuck60

Member
At Q7802
Pins:
1-GND
2-P3V3_S4_EN= 479mv
3-P3V3SUS_EN_L= 3.3v
4-GND
5-PM_SUS_EN=0
6-PP3V3S4_EN_L=0

Q7820
Pins:
1- PP3V3_SUS=3.3v
2-P3V3SUS_SS=3.3v
3-PP3V3_S5=3.3v
4-PP3v3_S5=3.3v
 

Chuck60

Member
Ok I grounded SMC_ONOFF_L at c5710 and the PM_PWRBTN_L at R2502 Ok yes it did drop down to 400mv and went back up to 1.6v
 

2informaticos

Administrator
Staff member
"yes it did drop down to 400mv and went back up to 1.6v"
It should have 3.3V in normal state; check it with KB disconnected.
 

2informaticos

Administrator
Staff member
"it did drop down to 400mv and went back up to 1.6v"
Then what this mean?

Check if all PM_SLP_Sx_L signals pulse at same time when PM_PWRBTN_L drops.
 

Chuck60

Member
Ok my mistake. When you ask me to short SMC_ONOFF_L to ground and check to see if I had a drop in voltage at PM_PWRBTN_L yes it does drop down to 400mv and then back up to 1.6v and when I said "it did drop down to 400mv and went back up to 1.6v" I was referring to PM_PWRBTN_L
I will check to see if all the sleep signals “PM_SLP_Sx_L” pulse at the same time as
“ PM_PWRBTN_L” thank you for your help
 
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2informaticos

Administrator
Staff member
PM_PWRBTN_L also MUST go back to 3V when you realease power button.
In fact, it should be steady 3V and only drops when SMC_ONOFF_L is triggered.
 

Chuck60

Member
Ok on R1985 on pin 1 =3.3v on pin 2=1.6v
I removed R1985 and measured it is 1k what schematic say is correct. When I power the board with out resistor I get pin 1= 3.3v and pin 2 = 1.6v so the 1.6 is either coming from smc or pch. I get 1.6v from Both pins of r2502 With R1985, R2585 removed. But on the schematic it say “in” to smc :( so is this signal being sent by pch low ? Or should I remove R2502?

I will post the “PM_SLP_Sx_L“ signals as soon as I figure out why PM_PWRBTN_L is low as of now the sleep signals are 0v but I’m guessing that has a lot todo with the resistors I have removed.
 
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2informaticos

Administrator
Staff member
Either PCH, or SMC pull down PM_PWRBTN_L.
You can try heating PCH with quality flux, to discard an issue created by accumulated crap underneath.
Also do the same with SMC...
 
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