A1708 820-00840-A not asking for 20v (LR343)

[briancomputerdoctor]

Motherboard looks fine but only asking for 5v on both usb-c.

U3100 Pin 2 PP1v8_UPC_XA_LDOD = 1.8v, 0.46,, Pin 12 PP3v3_UPC_XA__LDO = 3.39v, 0.486,, Pin 35 PP1v1_UPC_XA_LDO = 1.1v, 0.467,, Pin 75 PP1v8_UPC_XA_LDO = 1.79v, 0.49.

U3200 Pin 2 PP1v8_UPC_XB_LDOD = 1.79v, 0.457,, Pin 12 PP3v3_UPC_XB__LDO = 3.37v, 0.486,, Pin 35 PP1v1_UPC_XB_LDO = 1.1v, 0.458,, Pin 75 PP1v8_UPC_XB_LDO = 1.8v, 0.487.

PP3v3_G3H = 3.41v, 0.339.

DIV_PPBUS_G3H = 0v, OL.

 

[2informaticos]

Any history available?

Do you get OL in diode mode at F7000?
Be sure to check it correctly.

 

[briancomputerdoctor]

The customer says that one day it was working and the next not. So far I cannot see any signs of corrosion on any component. The keyboard keys in the bottom right show signs that there may have been a spillage at some point. They are not springing back up as fast as the other keys, but it is only a minor difference. I have found no liquid. The fan is under this part of the keyboard. I have extracted the fan and see no damage.

I get 0.417 on diode mode at F7000.

 

[2informaticos]

If PPBUS_G3H is not present, post basic voltages for U7000; P_IN, AUX_DET, VDDA/P, SMC_RST*, AUX_OK, A/BMON.

 

[briancomputerdoctor]

No, apologies. That was DIV_PPBUS_G3H.

PPBUS_G3H is giving 13.04v and 0.400

 

[briancomputerdoctor]

PPVIN_G3H_P3V3G3H 12.73v
CHGR_BMON 0v
TBA_VDDP 5.11v
TBA_AUX_DET 1.25v
CHGR_AMON 0v
SMC_AUX_OK 3.41v
SMC_RST_IN 0v
TBA_VDDA 5.11v

 

[2informaticos]

No reason to check them, if PPBUS_G3H has correct voltage.

Do you get 3V3_S5?

 

[briancomputerdoctor]

Yes.

PP3V3_S5 gives 3.32v

 

[2informaticos]

Trigger SMC_ONOFF_L and check for drop pulse at PCH_PWRBTN_L (at same time).

 

[briancomputerdoctor]

Trigger SMC_ONOFF_L and check for drop pulse at PCH_PWRBTN_L (at same time).

Could you explain this procedure in more detail, please.

 

[2informaticos]

HOW TO collection

I hope this "How to" collection will help our members. I will possibly modify this post in time, if updates available. Trigger SMC_ONOFF_L (PMU_ONOFF_L): It reffers to simulate power button function, when the keyboard is not connected. We need to do this when we work with the board...

boards.rossmanngroup.com

 

[briancomputerdoctor]

When I trigger SMC_ONOFF_L to ground there is no change at PCH_PWRBTN_L.

Stays at 3.3v

 

[2informaticos]

Did you check it at same time when trigger SMC_ONOFF_L?
If no reaction, the problem should be on SMC, or PMIC areas.

Do you get 13V at PPBUS_G3H, but still 5V on both USB-C inputs?

 

[briancomputerdoctor]

Yes, at the same time.

Correct. 5v on both usbc and 13v on PPBUS_G3H

 

[briancomputerdoctor]

I checked again and PCH_PWRBTN_L is dropping to 0.34v

I don't understand why that didn't happen the first time. I was doing it simultaneously.

 

[2informaticos]

If PCH_PWRBTN_L reacts, means SMC sends the signal to PCH.
Now check for pulse at PM_SLP_S4_L, at same time.

 

[briancomputerdoctor]

I plugged in the power this morning and it's getting 20v
I didn't change anything.

 

[briancomputerdoctor]

I connected the drive and it booted, but showed signs of gfx failure.

 

[2informaticos]

Can be CPU, or RAM issue.
Boot menu is showed correctly?

 

[briancomputerdoctor]

Yes. Displayed correctly until after i put password in and it was loading into the operating system. When it got to the desktop it looked better but not perfect. It ran sluggishly for an hour before I powered it off.