[SOLVED]820-3115 no pp3v3s0

[nate8organic]

liquid damaged board. has other repair shop work on it. i have no pp3v3s0 but i have 3.34v on pin 1 of c7830. 0 on pin 2. cannot seem to figure out what is holding that down or not letting it turn on. i did jump pin 1 to pin 2 of c7830 and i got 2.53v on all of the pp3v3S0 lines if that helps any.

 

[dukefawks]

Why are you not checking if P3V3S0_EN is present? And if missing is PM_SLP_S3_L present. If not what is resistance to GND on this line?

 

[nate8organic]

Yes i have 3v3 on _EN. Res is 13k on c7830 pin 1. 102.8k on pin 1 of c7830 and 11.4k on pin 2.

 

[dukefawks]

Well if P3V3S0_EN is present then pin 3 on Q7812 should be 0V and so pulling down the gate of Q7830 to 0V too.

 

[nate8organic]

just to make sure p3v3s0_en_L is p3v3s0_en? because there is no p3v3s0_en in the board view or pdf. pin 3 on the q7812 is p3v3s0_en i have 3v there not 0v. what is wrong or am i doing wrong?

 

[nate8organic]

fixed it. i found c5401 was missing could this have caused the issue? only asking because i reflowed the smc and then spotted the part missing so i put it on and the board was working. so couldn't tell if the smc re flow helped or not but am curious to know. anyway its fixed now.
Thanks.

 

[dukefawks]

C5401 does nothing of course..