820-2850 A No PPBUS_G3H

Neil250

Member
Very new to board repair

Green Light on charger

Decided to start with U7000

R7020: 0 VOLTS
PPDCIN_G3H: 18.5V
Q7080: SOURCE: 18.5V GATE: 17.88 DRAIN: 18.03
Q7085: SOURCE: 18.03V GATE: 17.23 DRAIN: 0V

R7085 actually sparked when I tested it

R7020: 0 VOLTS (PPBUS_G3H_DCINRUSH)

U7000: RESISTANCE PINS 27-28 20.3 OHMS (CURRENT SENSING)

F7040 Fuse: pin 2: 0 V (starts at 1 and slowly drifts to 0)

U7000
PIN 14: SMC_BC_ACOK: 3.27V
PIN 19: 5.1 V



My thought is that Q7085 is bad. Should have voltage going through it. Without that, no PPBUS_G3H

Am I on the right track?
 

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2informaticos

Administrator
Staff member
Q7085 is blocked; is controlled by U7000.
Post basic voltages for U7000; pins 1, 2, 3, 9, 12, 13, 15, 17, 19, 20, 27.
Also post exact ohm resistance between pins 17/18.

Need to know exact values for R7085/86; ohm scale, measured onboard.
 

Neil250

Member
Post basic voltages for U7000;
pins

1: 16.70
2: 18.24
3: 0.206
9: 0.030
12: 3.412
13: 3.41
15: 0.048
17: 0.233
19: 5.115
20: 5.115
27: 0
28: 0

RESISTANCE 17/18: 3.5 ohm

R7085: 470 Kohm
R7086: 331 Kohm
 

Neil250

Member
R7010: 4 kOhm
R7011: 330 Ohm
C7011: 0 uF

R7013 is missing completely which makes no sense to me (I double and triple checked)
R7012: 1 kOhm
 
Last edited:

2informaticos

Administrator
Staff member
"R7011: 330 Ohm"
Do you mean onboard value?
Remove C7011.
If you still get the same value, change U7000.

"C7011: 0 uF"
I was not thinking on its capacity...
 

Neil250

Member
"R7011: 330 Ohm"
Do you mean onboard value?

"C7011: 0 uF"
I was not thinking on its capacity...


Were you asking about short to ground or?

Sorry, new to this but I do appreciate your time.
After your response I usually spend time looking at the schematic to figure how and why to ask the same question you did.
 

2informaticos

Administrator
Staff member
ACIN input measured on diode mode gave very low value on your board.
Only two options available:
- C7011 leakage, can be discarded measuring after removed.
- U7000 internal problems and needs change.
 

2informaticos

Administrator
Staff member
R7012/13 can NOT be present at same time.
R7012 is for 3 cells battery and R7013 for 2 cells battery.
If none present, U7000 will deliver aprox 4V on PPBUS_G3H; it will suppose 1 cell battery present...
 
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