820-00840 No PP3V3_G3H

[KootenayMacGuy]

Hi there. I have an 820-00840. No power. Stuck at 5v and 0A from charger. There was some corrosion around CD3215's so I replaced with brand new ones (from your store) as well as ISL9239 (new) and U6990.

PPVIN _G3H is 5V going into U6990 but there is no PM_EN_P3V3_G3H coming from ISL9239 even after replacing.

Where do I go from here?

 

[2informaticos]

Post diode mode to ground at L6995 and F7000.

 

[KootenayMacGuy]

PS there is no short to ground on PP3V3_G3H

 

[KootenayMacGuy]

L6995 diode is 1.55V
F7000 is 2.6v and going up

 

[2informaticos]

Did you properly measure in diode mode???

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

 

[KootenayMacGuy]

I apologize. I had my leads reversed:
L6995: 0.376
F7000: 0.445

 

[2informaticos]

Post U7000 basic voltages; P_IN, AUX_DET, VDDA/P, SMC_RST*, AUX_OK, A/BMON.

 

[KootenayMacGuy]

P_IN: 5.117
AUX_DET: 1.272
VDDA/P: 5.017
SMC_RST_L: 0.000V
SMC_RST_IN: 0.001V
AUX_OK: 0.221V
CHGR_BMON: 0.000V
CHGR_AMON: 0.000V

 

[2informaticos]

Change U7000...

 

[KootenayMacGuy]

U7000 has been replaced again (NEW), as well as another set of CD3215's (NEW) as well as U6990 (NEW). 5.19V on the charger pulling 40 milliamps.

PP3V3_G3H is 4.25V now. What would be causing this overvoltage? Where should I look next?

 

[2informaticos]

So now you get 5V at PM_EN_P3V3_G3H?

Corroded resistor on R6993-97 divider, will change 3V3_G3H voltage.
R6995/97 went high, or R6993/96 decreased values.

 

[KootenayMacGuy]

PM_EN_P3V3_G3H is 4.63V

R6993 tests good
R6995 good
R6996 good
R6997 good


P_IN: 4.63
AUX_DET: 1.155
VDDA/P: 4.633/4.632
SMC_RST_L: 0.000V
SMC_RST_IN: 0.001V
AUX_OK: 4.246V
CHGR_BMON: 0.005V
CHGR_AMON: 0.007V

 

[2informaticos]

Try 100K instead of 115K for R6995.

 

[KootenayMacGuy]

changed R6995 to 100K. Same result.

 

[2informaticos]

R6999 voltage didn't change at all?

 

[KootenayMacGuy]

No change. 4.24V

 

[2informaticos]

Then change U6990.
It should react when modify the feedback divider.