820-3435-B Orange light but not turn on

Dewanbd

Member
It was water damaged near U7501 and pin25, sw2, P3V3_S5_LL is missing, so should i changed U7501 or q7560 ?
 

2informaticos

Administrator
Staff member
24/25 are the control pins for the gate of high-side MOSFET Q7560.
It will never allow current flow if pin 25/U7501 is not soldered.
Change the chip if its pad is damaged; repair trace if is corroded.
Change Q7560 if is bad only.
Check for short/low value on L7520/60.
Be sure R/C7564 are OK.
 
Last edited:

Dewanbd

Member
i changed both U7501 and Q7560. No short on L720/60. R/C7564 are ok. Now there is no light and not turn on too.
 

2informaticos

Administrator
Staff member
Trace of pin25/U7501 to Q7560 is OK; resolder all its pins too.
Post basic voltages for U7501.

Also post PPBUS_G3H and 3V42.
 

2informaticos

Administrator
Staff member
"Now there is no light
------------------
PPBUS_G3H=8.2v"
SMC is not working now...

Check basic signals and voltages for SMC at page 35, U5000 (2 of 2).
Start checking U5110.

"basic voltages for U7501"
I talk about pins 23, 13, 22, 29, 12, 21...
 

Dewanbd

Member
it was missing Q3080, i add it and now
U5110:
P1=3.41, P3=3.41V,P4=1.7V, P5=3.3V, P6=3.3V, P8=3.2, P7=3.4V

U5000:
c5021,PP3V3_S5_AVREF_SMC=1.2v
PP1V2_S5_SMC_VDDC=1.2v
PP3V3_S5_SMC_VDDA=3.41
 

2informaticos

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Staff member
"c5021,PP3V3_S5_AVREF_SMC=1.2v"
Are you sure???
Voltage comes from pin 1/U5110...

"Check basic signals and voltages for SMC"
And what about signals?
 

Dewanbd

Member
c5021,PP3V3_S5_AVREF_SMC=3.29V ( you are genious! )
Voltage comes from pin 1/U5110=3.4V
I dont have oscilloscope , i dont know how to check signal.
 

2informaticos

Administrator
Staff member
You may need o-scope only for SMC_E/XTAL and SMC_CLK32K; the last is not present before 3V3_SUS.
However, 0.45V DC on it points to oscillation presence; 80% probability...
The 4 SMC_Txx signals no need o-scope, only DMM; as SMC_RESET_L too.
 

2informaticos

Administrator
Staff member
Don't you have DMM???
What you used before?
A cheap digital multimeter can be achieved for less than 10 bucks...
 
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