Dear Members,
When the laptop is cold, if I turn it on, it boots fine and gives display.
Then after 10 to 60 seconds (randomly), the VCCSA voltage gets 0v and the laptop shows white screen. then after 3 seconds, the laptop turns off.
Then if I turn the laptop on, VCCSA is zero and the laptop has black screen. then I have to wait about 15-30 minutes to get picture on this laptop.
VCCSA is generated by RT8209B (PU601). Here is the link to the schematics. PU601 is on Page 50:
https://www.badcaps.net/forum/attach...7&d=1591338538
when it gives display, the pins are as follows:
Pin 1 (En): 3.3v
Pin 2 (Ton): 2v
Pin 3 (Vout):
Pin 4 (VDD): 5v
Pin 5 (FB):
Pin 6 (PGOOD): 3.3v
Pin 7 (GND): 0v
Pin 8 (PGND): 0v
Pin 9 (LGATE): ?
Pin 10 (VDDP): 5v
Pin 11 (CS): 0v
Pin 12 (PHASE): ?
Pin 13 (UGATE): ?
Pin 14 (BOOT): 5.8v
VCCSA : 0.9v
when it does not give display, the pins are as follows:
Pin 1 (En): 3.3v
Pin 2 (Ton): 0.02v
Pin 3 (Vout): 0v
Pin 4 (VDD): 5v
Pin 5 (FB): 0v
Pin 6 (PGOOD): 0v
Pin 7 (GND): 0v
Pin 8 (PGND): 0v
Pin 9 (LGATE): ?
Pin 10 (VDDP): 5v
Pin 11 (CS): 0v
Pin 12 (PHASE): ?
Pin 13 (UGATE): ?
Pin 14 (BOOT): 4.6v
VCCSA : 0v
Neither PU601 nor its surrounding Mosfets/resistors/capacitors get warm. the Mosfets are not shorted.
resistance on VCCSA is about 40 Ohms.
Now I do not know whether PU601 needs to be replaced or one of its surrounding Mosfets/resistors/capacitors or the CPU is defective?
Please give your opinion.
I have doubt that the cpu may force PU601 stop its output voltage.
Thanks
When the laptop is cold, if I turn it on, it boots fine and gives display.
Then after 10 to 60 seconds (randomly), the VCCSA voltage gets 0v and the laptop shows white screen. then after 3 seconds, the laptop turns off.
Then if I turn the laptop on, VCCSA is zero and the laptop has black screen. then I have to wait about 15-30 minutes to get picture on this laptop.
VCCSA is generated by RT8209B (PU601). Here is the link to the schematics. PU601 is on Page 50:
https://www.badcaps.net/forum/attach...7&d=1591338538
when it gives display, the pins are as follows:
Pin 1 (En): 3.3v
Pin 2 (Ton): 2v
Pin 3 (Vout):
Pin 4 (VDD): 5v
Pin 5 (FB):
Pin 6 (PGOOD): 3.3v
Pin 7 (GND): 0v
Pin 8 (PGND): 0v
Pin 9 (LGATE): ?
Pin 10 (VDDP): 5v
Pin 11 (CS): 0v
Pin 12 (PHASE): ?
Pin 13 (UGATE): ?
Pin 14 (BOOT): 5.8v
VCCSA : 0.9v
when it does not give display, the pins are as follows:
Pin 1 (En): 3.3v
Pin 2 (Ton): 0.02v
Pin 3 (Vout): 0v
Pin 4 (VDD): 5v
Pin 5 (FB): 0v
Pin 6 (PGOOD): 0v
Pin 7 (GND): 0v
Pin 8 (PGND): 0v
Pin 9 (LGATE): ?
Pin 10 (VDDP): 5v
Pin 11 (CS): 0v
Pin 12 (PHASE): ?
Pin 13 (UGATE): ?
Pin 14 (BOOT): 4.6v
VCCSA : 0v
Neither PU601 nor its surrounding Mosfets/resistors/capacitors get warm. the Mosfets are not shorted.
resistance on VCCSA is about 40 Ohms.
Now I do not know whether PU601 needs to be replaced or one of its surrounding Mosfets/resistors/capacitors or the CPU is defective?
Please give your opinion.
I have doubt that the cpu may force PU601 stop its output voltage.
Thanks
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