820-3023-A No Power not charge

Djsp

Member
Hello
PP_3v42_G3H ok
PPBUS_G3H ok
I have examined the power supply circuit of the 5v and the 3v3
starting from C9487 up to U7101 and pin 25.
in both I find the voltage unstable, can the defect be Q7260?
 
Last edited:

2informaticos

Administrator
Staff member
What are you checking on thunderbolt power rail (C9487), if board doesn't even turn on?
No relation at all with Q7260 (3V3_S5).

Do you get correct SMC_RESET_L and SMC_ADAPTER_EN?
What is the exact PPBUS_G3H voltage (no battery connected)?
 

Djsp

Member
L7220 and 0 I measured U7201 and accidentally short circuited two pins now ppbus_g3h and 2.34v Maybe I created problems with U7000, pp3v3 no longer pulsates, I'm still a beginner
 

2informaticos

Administrator
Staff member
Always choose surrounding components as test points.
Avoid such problems touching directly chip pins.

Post diode mode to ground at PPBUS_G3H and L7220/60; red probe on ground.
 

Djsp

Member
I found a hole on Q7260 and replace it on L8220 I don't have low insulation. I removed F7040 to see the short on ppbus_g3h, but now I get 3.24v is it not that I have to replace u7000? One last question, I found Q7260 on a SIZ710DT donor card only that instead of 17W, there is 15W I have to check the data sheet or well the same?
 

2informaticos

Administrator
Staff member
No problem, if pads layout is the same for both.

Did you check if Q7220 is shorted D-S?
Changing Q7260 doesn't eliminate the short to ground from L7220.
 

Djsp

Member
So, I replaced Q7260 and pp3v3 returned PPBUS_g3H also returned to normal value, on L7220 I found C7252 with low insulation. But is U1800 normal for it to be very hot? Or did I create problems with it? Now I only have 5V S3 to restore
 

2informaticos

Administrator
Staff member
Guess what happened when Q7260 got burnt.
If PCH gets very hot now, when only 3V power rails are available on the board, then is dead.

As board is in off state, only RTC and system power management blocks of PCH are powered up.
No reason at all to get even warm.
 
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