Working on a board that had liquid, but was cleaned "hard" by someone; i.e., it looks like it's gone through either 2-3 cleanings (lots of white scaly buildup on everything), or maybe a long cleaning (5-10 minutes) in an UC. I can still spot tiny indications of where the liquid was, but I'm pretty stumped by this one. I have some questions about diagnosing this:
1. This board has ppbus_g3h (8.56v), 3v42 (3.44v), 3v3_s5, 5v_s5, S5_PWRGD (at R8141), ppvrtc_g3h, etc.
2. Board is missing 3v3_s0, 5v_s0, etc. All S0 rails are missing, so board isn't getting to s0 of course.
3. On U7501: pin 4: .197v; pin 12: 3.42v; pin 21: 3.42v; pin 23: 3.3v. So I'm missing my EN1 (P5VS4RS3_EN_R) for U7501. Tracing this back...
4. PM_SLP_S4_L is .201v and S4_PWR_EN is 0v. I believe these are both sent out at the same time, which means something earlier is likely missing...
5. Found I'm also missing PM_SLP_SUS_L as well, but I do have PM_DSW_PWRGD (3.42v), so sounds like my SUS signal is my issue here...(uh oh, hopefully not dead CPU!)
6. At U8130: pin1 is present (3v3_s5), but I don't have PP3v3_SUS. Looks like this is required before PM_SLP_S5_L, even, so I believe we need to start here, right?
7. Looking at p3v3sus_en...I've got 0v at both pins of R8190. So now I'm missing p3v3sus_en and PM_SLP_SUS_L, which is where I get stuck. Really hoping it's not a dead CPU. Maybe a clock issue? No signs of liquid near clock, and my vrtc is proper, but maybe it's damaged anyway.
I replaced U8130 to be safe, and no change. Still no pp3v3_sus, etc.
I think I've offered enough information on this one, but if not, please let me know. Seems I need to get my PM_SLP_SUS_L situated first. If this is not correct, please let me know! Thanks, Duke and Aprendiz.
1. This board has ppbus_g3h (8.56v), 3v42 (3.44v), 3v3_s5, 5v_s5, S5_PWRGD (at R8141), ppvrtc_g3h, etc.
2. Board is missing 3v3_s0, 5v_s0, etc. All S0 rails are missing, so board isn't getting to s0 of course.
3. On U7501: pin 4: .197v; pin 12: 3.42v; pin 21: 3.42v; pin 23: 3.3v. So I'm missing my EN1 (P5VS4RS3_EN_R) for U7501. Tracing this back...
4. PM_SLP_S4_L is .201v and S4_PWR_EN is 0v. I believe these are both sent out at the same time, which means something earlier is likely missing...
5. Found I'm also missing PM_SLP_SUS_L as well, but I do have PM_DSW_PWRGD (3.42v), so sounds like my SUS signal is my issue here...(uh oh, hopefully not dead CPU!)
6. At U8130: pin1 is present (3v3_s5), but I don't have PP3v3_SUS. Looks like this is required before PM_SLP_S5_L, even, so I believe we need to start here, right?
7. Looking at p3v3sus_en...I've got 0v at both pins of R8190. So now I'm missing p3v3sus_en and PM_SLP_SUS_L, which is where I get stuck. Really hoping it's not a dead CPU. Maybe a clock issue? No signs of liquid near clock, and my vrtc is proper, but maybe it's damaged anyway.
I replaced U8130 to be safe, and no change. Still no pp3v3_sus, etc.
I think I've offered enough information on this one, but if not, please let me know. Seems I need to get my PM_SLP_SUS_L situated first. If this is not correct, please let me know! Thanks, Duke and Aprendiz.